Merge branch 'sync' of git@gnuradio.org:trondeau into master

This merge adds polyphase clock recovery, implements new PAM demodulators
that use it, and also moves GRC examples to gnuradio-examples component.

See merge commit diff for updated files post merge.

* 'sync' of git@gnuradio.org:trondeau: (54 commits)
  Reverting dqpsk to be mpsk_receiver based and not change its behavior.
  Fixing initialization of timing gains. Alpha should be < 1, and beta should be << 1.
  This splits the rate into a fractional an integer value, which allows the loop to adjust the fractional rate while the integer rate keeps the increments moving properly. Allows the max rate deviation to be independent of the integer rate. Scaling of the differential taps also allows alpha and beta to operate independent of the rate when fractional samples per symbol are used. Slightly more tolerant to large signal values, but they still should be close to +/-1.
  Fixing compiler warnings.
  Adding dqpsk2 block to makefile for installation.
  Adding DQPSK version that uses the PFB timing sync block (dqpsk2).
  Minor fixes for logging.
  Fixing import of UI file.
  Temporary working dbpsk2 example until we match everything.
  Working DBPSK implementation with new PFB clock recovery block. The feedforward AGC wasn't playing nicely, the frequency aquistion range was increased to swing half the sample rate in either direction, and the number of filter phases to use was increased to 32.
  A bit of code cleanup.
  Starting to rework QT app to control new PFB clock recovery alg.
  Making old dbpsk work again to compare against new version.
  Adding new DBPSK block with new PFB clock recovery alg.
  Revert "More additions to PAM timing simulation."
  More additions to PAM timing simulation.
  Using 2-PAM by default.
  Cleaning up GRC PAM timing example and adding ability to do M-ary PAM.
  Cleaning up constructor.
  Moving filter number decision to start work function.
  ...

28 files changed, 12279 insertions, 449 deletions

diff --git a/gnuradio-examples/Makefile.am b/gnuradio-examples/Makefile.am
index 360ae8b41..9ea890c12 100644
--- a/gnuradio-examples/Makefile.am
+++ b/gnuradio-examples/Makefile.am
@@ -1,5 +1,5 @@
 #
-# Copyright 2004,2007 Free Software Foundation, Inc.
+# Copyright 2004,2007,2009 Free Software Foundation, Inc.
 # 
 # This file is part of GNU Radio
 # 
@@ -23,5 +23,5 @@ include $(top_srcdir)/Makefile.common
 
 SUBDIRS = c++
 if PYTHON
-SUBDIRS += python
+SUBDIRS += python grc
 endif
diff --git a/gnuradio-examples/grc/.gitignore b/gnuradio-examples/grc/.gitignore
new file mode 100644
index 000000000..b336cc7ce
--- /dev/null
+++ b/gnuradio-examples/grc/.gitignore
@@ -0,0 +1,2 @@
+/Makefile
+/Makefile.in
diff --git a/gnuradio-examples/grc/Makefile.am b/gnuradio-examples/grc/Makefile.am
new file mode 100644
index 000000000..97417c5a2
--- /dev/null
+++ b/gnuradio-examples/grc/Makefile.am
@@ -0,0 +1,61 @@
+#
+# Copyright 2009 Free Software Foundation, Inc.
+#
+# This file is part of GNU Radio
+#
+# GNU Radio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GNU Radio is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GNU Radio; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+#
+
+include $(top_srcdir)/Makefile.common
+
+grc_examples_prefix = $(exampledir)/grc
+
+audiodatadir = $(grc_examples_prefix)/audio
+dist_audiodata_DATA = \
+	audio/dial_tone.grc \
+	audio/cvsd_sweep.grc
+
+demoddatadir = $(grc_examples_prefix)/demod
+dist_demoddata_DATA = \
+	demod/mpsk_demod.grc \
+	demod/pam_timing.grc
+
+simpledatadir = $(grc_examples_prefix)/simple
+dist_simpledata_DATA = \
+	simple/ber_simulation.grc \
+	simple/dpsk_loopback.grc \
+	simple/variable_config.grc \
+	simple/var_sink_taps.grc
+
+trellisdatadir = $(grc_examples_prefix)/trellis
+dist_trellisdata_DATA = \
+	trellis/readme.txt \
+	trellis/interference_cancellation.grc
+
+usrpdatadir = $(grc_examples_prefix)/usrp
+dist_usrpdata_DATA = \
+	usrp/usrp2_const_wave.grc \
+	usrp/usrp2_dpsk_mod.grc \
+	usrp/usrp2_fft.grc \
+	usrp/usrp_two_tone_loopback.grc \
+	usrp/usrp_wbfm_receive.grc
+
+xmlrpcdatadir = $(grc_examples_prefix)/xmlrpc
+dist_xmlrpcdata_DATA = \
+	xmlrpc/readme.txt \
+	xmlrpc/xmlrpc_client.grc \
+	xmlrpc/xmlrpc_client_script.py\
+	xmlrpc/xmlrpc_server.grc
diff --git a/gnuradio-examples/grc/audio/cvsd_sweep.grc b/gnuradio-examples/grc/audio/cvsd_sweep.grc
new file mode 100644
index 000000000..8d0b385ce
--- /dev/null
+++ b/gnuradio-examples/grc/audio/cvsd_sweep.grc
@@ -0,0 +1,918 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Sat Sep 19 20:30:08 2009</timestamp>
+  <block>
+    <key>import</key>
+    <param>
+      <key>id</key>
+      <value>import_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>import</key>
+      <value>import math</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(157, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blks2_cvsd_decode</key>
+    <param>
+      <key>id</key>
+      <value>blks2_cvsd_decode_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>resample</key>
+      <value>resample</value>
+    </param>
+    <param>
+      <key>bw</key>
+      <value>bw</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(887, 340)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_sig_source_x</key>
+    <param>
+      <key>id</key>
+      <value>tri_source</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>audio_rate</value>
+    </param>
+    <param>
+      <key>waveform</key>
+      <value>gr.GR_TRI_WAVE</value>
+    </param>
+    <param>
+      <key>freq</key>
+      <value>0.05</value>
+    </param>
+    <param>
+      <key>amp</key>
+      <value>0.5</value>
+    </param>
+    <param>
+      <key>offset</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(44, 316)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_throttle</key>
+    <param>
+      <key>id</key>
+      <value>throttle</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>samples_per_second</key>
+      <value>audio_rate</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(238, 348)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_vco_f</key>
+    <param>
+      <key>id</key>
+      <value>vco</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>audio_rate</value>
+    </param>
+    <param>
+      <key>sensitivity</key>
+      <value>audio_rate*2*math.pi</value>
+    </param>
+    <param>
+      <key>amplitude</key>
+      <value>0.9</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(427, 332)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blks2_cvsd_encode</key>
+    <param>
+      <key>id</key>
+      <value>enc</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>resample</key>
+      <value>resample</value>
+    </param>
+    <param>
+      <key>bw</key>
+      <value>bw</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(655, 340)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_packed_to_unpacked_xx</key>
+    <param>
+      <key>id</key>
+      <value>p2u</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>bits_per_chunk</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>endianness</key>
+      <value>gr.GR_MSB_FIRST</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(648, 415)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_char_to_float</key>
+    <param>
+      <key>id</key>
+      <value>c2f</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(676, 483)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>audio_sink</key>
+    <param>
+      <key>id</key>
+      <value>audio_sink</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>audio_rate</value>
+    </param>
+    <param>
+      <key>device_name</key>
+      <value>plughw:0,0</value>
+    </param>
+    <param>
+      <key>ok_to_block</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1127, 340)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>audio_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>8000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(251, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>resample</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(344, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>bw</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.5</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(431, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>notebook</key>
+    <param>
+      <key>id</key>
+      <value>displays</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.NB_TOP</value>
+    </param>
+    <param>
+      <key>labels</key>
+      <value>['Original','Encoded','Decoded']</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(12, 106)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_fftsink2</key>
+    <param>
+      <key>id</key>
+      <value>orig_fft</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Original Spectrum</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>audio_rate</value>
+    </param>
+    <param>
+      <key>baseband_freq</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>y_per_div</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>y_divs</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ref_scale</key>
+      <value>2.0</value>
+    </param>
+    <param>
+      <key>fft_size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>fft_rate</key>
+      <value>30</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>0, 0, 1, 1</value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value>displays, 0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(415, 97)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_scopesink2</key>
+    <param>
+      <key>id</key>
+      <value>orig_scope</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Original Waveform</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>audio_rate</value>
+    </param>
+    <param>
+      <key>v_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>t_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ac_couple</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>xy_mode</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>1, 0, 1, 1</value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value>displays, 0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(414, 425)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_fftsink2</key>
+    <param>
+      <key>id</key>
+      <value>enc_fft</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Encoded Spectrum</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>audio_rate*resample</value>
+    </param>
+    <param>
+      <key>baseband_freq</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>y_per_div</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>y_divs</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ref_scale</key>
+      <value>2.0</value>
+    </param>
+    <param>
+      <key>fft_size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>fft_rate</key>
+      <value>30</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>1, 0, 1, 1</value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value>displays, 1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(610, 551)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_scopesink2</key>
+    <param>
+      <key>id</key>
+      <value>enc_scope</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Encoded Waveform</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>audio_rate*resample</value>
+    </param>
+    <param>
+      <key>v_scale</key>
+      <value>0.5</value>
+    </param>
+    <param>
+      <key>t_scale</key>
+      <value>20.0/(audio_rate*resample)</value>
+    </param>
+    <param>
+      <key>ac_couple</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>xy_mode</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>0, 0, 1, 1</value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value>displays, 1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(858, 591)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_fftsink2</key>
+    <param>
+      <key>id</key>
+      <value>dec_fft</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Decoded Spectrum</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>audio_rate</value>
+    </param>
+    <param>
+      <key>baseband_freq</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>y_per_div</key>
+      <value>5</value>
+    </param>
+    <param>
+      <key>y_divs</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ref_scale</key>
+      <value>0.1</value>
+    </param>
+    <param>
+      <key>fft_size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>fft_rate</key>
+      <value>30</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>0, 0, 1, 1</value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value>displays, 2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(891, 98)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_scopesink2</key>
+    <param>
+      <key>id</key>
+      <value>dec_scope</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Decoded Waveform</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>audio_rate</value>
+    </param>
+    <param>
+      <key>v_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>t_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ac_couple</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>xy_mode</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>1, 0, 1, 1</value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value>displays, 2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(889, 422)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>cvsd_sweep</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>CVSD Vocoder Test</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>vco</source_block_id>
+    <sink_block_id>orig_fft</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>tri_source</source_block_id>
+    <sink_block_id>throttle</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>throttle</source_block_id>
+    <sink_block_id>vco</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>vco</source_block_id>
+    <sink_block_id>enc</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>enc</source_block_id>
+    <sink_block_id>blks2_cvsd_decode_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>vco</source_block_id>
+    <sink_block_id>orig_scope</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blks2_cvsd_decode_0</source_block_id>
+    <sink_block_id>dec_fft</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blks2_cvsd_decode_0</source_block_id>
+    <sink_block_id>dec_scope</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blks2_cvsd_decode_0</source_block_id>
+    <sink_block_id>audio_sink</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>enc</source_block_id>
+    <sink_block_id>p2u</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>p2u</source_block_id>
+    <sink_block_id>c2f</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>c2f</source_block_id>
+    <sink_block_id>enc_fft</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>c2f</source_block_id>
+    <sink_block_id>enc_scope</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gnuradio-examples/grc/audio/dial_tone.grc b/gnuradio-examples/grc/audio/dial_tone.grc
new file mode 100644
index 000000000..ac8cbef27
--- /dev/null
+++ b/gnuradio-examples/grc/audio/dial_tone.grc
@@ -0,0 +1,375 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Thu Jul 24 14:27:48 2008</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>dial_tone</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Dial Tone</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value>Example</value>
+    </param>
+    <param>
+      <key>description</key>
+      <value>example flow graph</value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_add_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_add_xx</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>3</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(513, 277)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>audio_sink</key>
+    <param>
+      <key>id</key>
+      <value>audio_sink</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>32000</value>
+    </param>
+    <param>
+      <key>device_name</key>
+      <value/>
+    </param>
+    <param>
+      <key>ok_to_block</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(699, 112)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_noise_source_x</key>
+    <param>
+      <key>id</key>
+      <value>gr_noise_source_x</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>noise_type</key>
+      <value>gr.GR_GAUSSIAN</value>
+    </param>
+    <param>
+      <key>amp</key>
+      <value>noise</value>
+    </param>
+    <param>
+      <key>seed</key>
+      <value>42</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(238, 380)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_sig_source_x</key>
+    <param>
+      <key>id</key>
+      <value>gr_sig_source_x</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>waveform</key>
+      <value>gr.GR_COS_WAVE</value>
+    </param>
+    <param>
+      <key>freq</key>
+      <value>440</value>
+    </param>
+    <param>
+      <key>amp</key>
+      <value>ampl</value>
+    </param>
+    <param>
+      <key>offset</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(240, 208)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_sig_source_x</key>
+    <param>
+      <key>id</key>
+      <value>gr_sig_source_x0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>waveform</key>
+      <value>gr.GR_COS_WAVE</value>
+    </param>
+    <param>
+      <key>freq</key>
+      <value>350</value>
+    </param>
+    <param>
+      <key>amp</key>
+      <value>ampl</value>
+    </param>
+    <param>
+      <key>offset</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(240, 38)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>ampl</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Volume</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>.4</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>.5</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>slider_type</key>
+      <value>horizontal</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>0, 0, 1, 2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(634, 413)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>noise</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Noise</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>.005</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>.2</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>slider_type</key>
+      <value>horizontal</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>1, 0, 1, 2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(443, 412)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(11, 171)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>gr_sig_source_x0</source_block_id>
+    <sink_block_id>gr_add_xx</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_sig_source_x</source_block_id>
+    <sink_block_id>gr_add_xx</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_noise_source_x</source_block_id>
+    <sink_block_id>gr_add_xx</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>2</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_add_xx</source_block_id>
+    <sink_block_id>audio_sink</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gnuradio-examples/grc/demod/mpsk_demod.grc b/gnuradio-examples/grc/demod/mpsk_demod.grc
new file mode 100644
index 000000000..08108dcba
--- /dev/null
+++ b/gnuradio-examples/grc/demod/mpsk_demod.grc
@@ -0,0 +1,586 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Mon Oct  5 18:34:52 2009</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>mpsk_demod</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>MPSK Demod Demo</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 170)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>random_source_x</key>
+    <param>
+      <key>id</key>
+      <value>random_source_x_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>2**8</value>
+    </param>
+    <param>
+      <key>num_samps</key>
+      <value>10000</value>
+    </param>
+    <param>
+      <key>repeat</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(155, 160)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blks2_dxpsk_mod</key>
+    <param>
+      <key>id</key>
+      <value>blks2_dxpsk_mod_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>dqpsk</value>
+    </param>
+    <param>
+      <key>samples_per_symbol</key>
+      <value>samps_per_sym</value>
+    </param>
+    <param>
+      <key>excess_bw</key>
+      <value>0.35</value>
+    </param>
+    <param>
+      <key>gray_code</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>verbose</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>log</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(391, 54)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_throttle</key>
+    <param>
+      <key>id</key>
+      <value>gr_throttle_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>samples_per_second</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(654, 142)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>samps_per_sym</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>4</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(7, 89)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_channel_model</key>
+    <param>
+      <key>id</key>
+      <value>gr_channel_model_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>noise_voltage</key>
+      <value>noise</value>
+    </param>
+    <param>
+      <key>freq_offset</key>
+      <value>freq_off</value>
+    </param>
+    <param>
+      <key>epsilon</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>seed</key>
+      <value>42</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(487, 282)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>noise</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Noise</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>.1</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(259, 353)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>freq_off</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Freq Offset</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>-.5</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>.5</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(126, 345)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>notebook</key>
+    <param>
+      <key>id</key>
+      <value>notebook</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.NB_TOP</value>
+    </param>
+    <param>
+      <key>labels</key>
+      <value>['Constellation', 'Spectrum']</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(520, 407)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_constellationsink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_constellationsink2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Constellation Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>frame_rate</key>
+      <value>5</value>
+    </param>
+    <param>
+      <key>const_size</key>
+      <value>2048</value>
+    </param>
+    <param>
+      <key>M</key>
+      <value>4</value>
+    </param>
+    <param>
+      <key>theta</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>0.005</value>
+    </param>
+    <param>
+      <key>fmax</key>
+      <value>0.06</value>
+    </param>
+    <param>
+      <key>mu</key>
+      <value>0.5</value>
+    </param>
+    <param>
+      <key>gain_mu</key>
+      <value>0.005</value>
+    </param>
+    <param>
+      <key>symbol_rate</key>
+      <value>samp_rate/4.</value>
+    </param>
+    <param>
+      <key>omega_limit</key>
+      <value>0.005</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value>notebook, 0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(824, 212)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_fftsink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_fftsink2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>FFT Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>baseband_freq</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>y_per_div</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>y_divs</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>ref_scale</key>
+      <value>2.0</value>
+    </param>
+    <param>
+      <key>fft_size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>fft_rate</key>
+      <value>30</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value>notebook, 1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(847, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>random_source_x_0</source_block_id>
+    <sink_block_id>blks2_dxpsk_mod_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_throttle_0</source_block_id>
+    <sink_block_id>wxgui_constellationsink2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_throttle_0</source_block_id>
+    <sink_block_id>wxgui_fftsink2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blks2_dxpsk_mod_0</source_block_id>
+    <sink_block_id>gr_channel_model_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_channel_model_0</source_block_id>
+    <sink_block_id>gr_throttle_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gnuradio-examples/grc/demod/pam_timing.grc b/gnuradio-examples/grc/demod/pam_timing.grc
new file mode 100644
index 000000000..4e2a2f861
--- /dev/null
+++ b/gnuradio-examples/grc/demod/pam_timing.grc
@@ -0,0 +1,1424 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Mon Oct 12 17:54:59 2009</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>top_block</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value></value>
+    </param>
+    <param>
+      <key>author</key>
+      <value></value>
+    </param>
+    <param>
+      <key>description</key>
+      <value></value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>run_options</key>
+      <value>prompt</value>
+    </param>
+    <param>
+      <key>run</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_uchar_to_float</key>
+    <param>
+      <key>id</key>
+      <value>gr_uchar_to_float_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(217, 108)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_uchar_to_float</key>
+    <param>
+      <key>id</key>
+      <value>gr_uchar_to_float_0_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(216, 273)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(128, 9)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>freq_offset</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Frequency Offset</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>-0.5</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>0.5</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(293, 684)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>rrctaps</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>firdes.root_raised_cosine(nfilts,1.0,1.0/(spb*nfilts), .35, int(11*spb*nfilts))</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(513, 679)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>random_source_x</key>
+    <param>
+      <key>id</key>
+      <value>random_source_x_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>pam_amp</value>
+    </param>
+    <param>
+      <key>num_samps</key>
+      <value>10000</value>
+    </param>
+    <param>
+      <key>repeat</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(13, 80)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>random_source_x</key>
+    <param>
+      <key>id</key>
+      <value>random_source_x_0_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>pam_amp</value>
+    </param>
+    <param>
+      <key>num_samps</key>
+      <value>10000</value>
+    </param>
+    <param>
+      <key>repeat</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(15, 245)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>const_source_x</key>
+    <param>
+      <key>id</key>
+      <value>const_source_x_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>-0.5*(pam_amp-1)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(213, 197)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>const_source_x</key>
+    <param>
+      <key>id</key>
+      <value>const_source_x_0_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>-0.5*(pam_amp-1)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(200, 360)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_scopesink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_scopesink2_0_0_0_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Scope Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>v_scale</key>
+      <value>1.25</value>
+    </param>
+    <param>
+      <key>t_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ac_couple</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>xy_mode</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value>notebook_0,2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1111, 767)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_scopesink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_scopesink2_0_0_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Scope Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>v_scale</key>
+      <value>9</value>
+    </param>
+    <param>
+      <key>t_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ac_couple</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>xy_mode</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value>notebook_0,1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1112, 881)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_channel_model</key>
+    <param>
+      <key>id</key>
+      <value>gr_channel_model_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>noise_voltage</key>
+      <value>noise_amp</value>
+    </param>
+    <param>
+      <key>freq_offset</key>
+      <value>freq_offset</value>
+    </param>
+    <param>
+      <key>epsilon</key>
+      <value>interpratio</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>seed</key>
+      <value>42</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(59, 543)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_throttle</key>
+    <param>
+      <key>id</key>
+      <value>gr_throttle_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>samples_per_second</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(290, 575)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>notebook</key>
+    <param>
+      <key>id</key>
+      <value>notebook_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.NB_TOP</value>
+    </param>
+    <param>
+      <key>labels</key>
+      <value>['error', 'phase', 'freq', 'Resampled Signal']</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(729, 769)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_scopesink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_scopesink2_0_0_1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Error</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>v_scale</key>
+      <value>.5</value>
+    </param>
+    <param>
+      <key>t_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ac_couple</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>xy_mode</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value>notebook_0,3</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1115, 358)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_add_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_add_xx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(440, 167)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_add_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_add_xx_0_1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(430, 330)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_float_to_complex</key>
+    <param>
+      <key>id</key>
+      <value>gr_float_to_complex_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(590, 184)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_scopesink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_scopesink2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Scope Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>v_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>t_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ac_couple</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>xy_mode</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1116, 500)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(435, 686)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_pfb_clock_sync_ccf</key>
+    <param>
+      <key>id</key>
+      <value>gr_pfb_clock_sync_ccf_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>sps</key>
+      <value>spb</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>alpha</value>
+    </param>
+    <param>
+      <key>beta</key>
+      <value>beta</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>rrctaps</value>
+    </param>
+    <param>
+      <key>filter_size</key>
+      <value>nfilts</value>
+    </param>
+    <param>
+      <key>init_phase</key>
+      <value>16</value>
+    </param>
+    <param>
+      <key>max_dev</key>
+      <value>1.5</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(512, 527)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>noise_amp</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Channel Noise</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(168, 684)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>interpratio</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Timing Offset</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1.00</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0.99</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>1.01</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(40, 684)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>spb_gen</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>4</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(119, 841)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>beta</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Timing Beta</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>0.1</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(668, 5)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>alpha</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Timing Alpha</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(552, 4)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_scopesink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_scopesink2_0_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Error</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>v_scale</key>
+      <value>3</value>
+    </param>
+    <param>
+      <key>t_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ac_couple</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>xy_mode</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value>notebook_0,0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1110, 651)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>root_raised_cosine_filter</key>
+    <param>
+      <key>id</key>
+      <value>root_raised_cosine_filter_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>interp_fir_filter_ccf</value>
+    </param>
+    <param>
+      <key>decim</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>interp</key>
+      <value>spb_gen</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>2*spb_gen</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>sym_rate</key>
+      <value>1./spb_gen</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>0.35</value>
+    </param>
+    <param>
+      <key>ntaps</key>
+      <value>11*spb_gen</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(834, 157)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blks2_pfb_arb_resampler_ccf</key>
+    <param>
+      <key>id</key>
+      <value>blks2_pfb_arb_resampler_ccf_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>rate</key>
+      <value>float(spb)/float(spb_gen)</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>firdes.low_pass(128, 128, 0.45, 0.1)</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>128</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(617, 374)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_multiply_const_vxx</key>
+    <param>
+      <key>id</key>
+      <value>gr_multiply_const_vxx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>sig_amp</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1096, 197)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>pam_amp</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(223, 9)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>spb</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>4.1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(32, 842)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>sig_amp</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(315, 9)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>gr_pfb_clock_sync_ccf_0</source_block_id>
+    <sink_block_id>wxgui_scopesink2_0_0</sink_block_id>
+    <source_key>1</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_pfb_clock_sync_ccf_0</source_block_id>
+    <sink_block_id>wxgui_scopesink2_0_0_0</sink_block_id>
+    <source_key>3</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_pfb_clock_sync_ccf_0</source_block_id>
+    <sink_block_id>wxgui_scopesink2_0_0_0_0</sink_block_id>
+    <source_key>2</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>random_source_x_0</source_block_id>
+    <sink_block_id>gr_uchar_to_float_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_uchar_to_float_0</source_block_id>
+    <sink_block_id>gr_add_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>const_source_x_0</source_block_id>
+    <sink_block_id>gr_add_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_uchar_to_float_0_0</source_block_id>
+    <sink_block_id>gr_add_xx_0_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>const_source_x_0_0</source_block_id>
+    <sink_block_id>gr_add_xx_0_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>random_source_x_0_0</source_block_id>
+    <sink_block_id>gr_uchar_to_float_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blks2_pfb_arb_resampler_ccf_0</source_block_id>
+    <sink_block_id>gr_channel_model_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blks2_pfb_arb_resampler_ccf_0</source_block_id>
+    <sink_block_id>wxgui_scopesink2_0_0_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_channel_model_0</source_block_id>
+    <sink_block_id>gr_throttle_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_throttle_0</source_block_id>
+    <sink_block_id>gr_pfb_clock_sync_ccf_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_pfb_clock_sync_ccf_0</source_block_id>
+    <sink_block_id>wxgui_scopesink2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_add_xx_0</source_block_id>
+    <sink_block_id>gr_float_to_complex_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_add_xx_0_1</source_block_id>
+    <sink_block_id>gr_float_to_complex_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_float_to_complex_0</source_block_id>
+    <sink_block_id>root_raised_cosine_filter_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>root_raised_cosine_filter_0</source_block_id>
+    <sink_block_id>gr_multiply_const_vxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>blks2_pfb_arb_resampler_ccf_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gnuradio-examples/grc/simple/ber_simulation.grc b/gnuradio-examples/grc/simple/ber_simulation.grc
new file mode 100644
index 000000000..618add29c
--- /dev/null
+++ b/gnuradio-examples/grc/simple/ber_simulation.grc
@@ -0,0 +1,564 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Thu Mar 19 11:08:59 2009</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>ber_sim</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>BER Simulation</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value>Example</value>
+    </param>
+    <param>
+      <key>description</key>
+      <value>Adjust the noise and constellation... see what happens!</value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(16, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_noise_source_x</key>
+    <param>
+      <key>id</key>
+      <value>gr_noise_source_x</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>noise_type</key>
+      <value>gr.GR_GAUSSIAN</value>
+    </param>
+    <param>
+      <key>amp</key>
+      <value>noise</value>
+    </param>
+    <param>
+      <key>seed</key>
+      <value>42</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(235, 379)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_chunks_to_symbols_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_chunks_to_symbols_xx</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>const</value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(360, 237)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_numbersink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_numbersink2</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>BER</value>
+    </param>
+    <param>
+      <key>units</key>
+      <value>%</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>base_value</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>min_value</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>max_value</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>factor</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>decimal_places</key>
+      <value>4</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>number_rate</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>show_gauge</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>1, 0, 1, 1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1062, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_throttle</key>
+    <param>
+      <key>id</key>
+      <value>gr_throttle</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>samples_per_second</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(397, 27)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blks2_error_rate</key>
+    <param>
+      <key>id</key>
+      <value>blks2_error_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>'BER'</value>
+    </param>
+    <param>
+      <key>win_size</key>
+      <value>1000000</value>
+    </param>
+    <param>
+      <key>bits_per_symbol</key>
+      <value>int(math.log(len(const))/math.log(2))</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(670, 41)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_constellation_decoder_cb</key>
+    <param>
+      <key>id</key>
+      <value>gr_constellation_decoder_cb</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>sym_position</key>
+      <value>const</value>
+    </param>
+    <param>
+      <key>sym_value_out</key>
+      <value>range(len(const))</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(708, 224)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>random_source_x</key>
+    <param>
+      <key>id</key>
+      <value>random_source_x</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>len(const)</value>
+    </param>
+    <param>
+      <key>num_samps</key>
+      <value>1000000</value>
+    </param>
+    <param>
+      <key>repeat</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(15, 244)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>noise</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>.25</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(18, 386)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>const</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1+1j, 1-1j, -1-1j, -1+1j</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(16, 461)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>50e3</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(20, 168)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>import</key>
+    <param>
+      <key>id</key>
+      <value>import</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>import</key>
+      <value>import math</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(138, 168)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_add_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_add_xx</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(652, 395)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_scopesink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_scopesink2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>"Constellation: "+str(const)</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>v_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>t_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ac_couple</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>xy_mode</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>2, 0, 1, 1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(828, 368)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blks2_error_rate</source_block_id>
+    <sink_block_id>wxgui_numbersink2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_throttle</source_block_id>
+    <sink_block_id>blks2_error_rate</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_constellation_decoder_cb</source_block_id>
+    <sink_block_id>blks2_error_rate</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_add_xx</source_block_id>
+    <sink_block_id>gr_constellation_decoder_cb</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_chunks_to_symbols_xx</source_block_id>
+    <sink_block_id>gr_add_xx</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_noise_source_x</source_block_id>
+    <sink_block_id>gr_add_xx</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>random_source_x</source_block_id>
+    <sink_block_id>gr_throttle</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>random_source_x</source_block_id>
+    <sink_block_id>gr_chunks_to_symbols_xx</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_add_xx</source_block_id>
+    <sink_block_id>wxgui_scopesink2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gnuradio-examples/grc/simple/dpsk_loopback.grc b/gnuradio-examples/grc/simple/dpsk_loopback.grc
new file mode 100644
index 000000000..6a507c98d
--- /dev/null
+++ b/gnuradio-examples/grc/simple/dpsk_loopback.grc
@@ -0,0 +1,450 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Tue Mar 17 12:53:37 2009</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>dpsk_loopback</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>DPSK Loopback</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value>Example</value>
+    </param>
+    <param>
+      <key>description</key>
+      <value>gnuradio flow graph</value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blks2_dxpsk_mod</key>
+    <param>
+      <key>id</key>
+      <value>blks2_dxpsk_mod_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>dbpsk</value>
+    </param>
+    <param>
+      <key>samples_per_symbol</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>excess_bw</key>
+      <value>0.35</value>
+    </param>
+    <param>
+      <key>gray_code</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(426, 295)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>10000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 170)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>freq</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Frequency (Hz)</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>500</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>samp_rate/2</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>slider_length</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>slider_type</key>
+      <value>horizontal</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(12, 257)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blks2_packet_encoder</key>
+    <param>
+      <key>id</key>
+      <value>blks2_packet_encoder_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>samples_per_symbol</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>bits_per_symbol</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>access_code</key>
+      <value></value>
+    </param>
+    <param>
+      <key>pad_for_usrp</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>payload_length</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(216, 260)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_throttle</key>
+    <param>
+      <key>id</key>
+      <value>gr_throttle_0_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>samples_per_second</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(225, 174)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_sig_source_x</key>
+    <param>
+      <key>id</key>
+      <value>gr_sig_source_x_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>waveform</key>
+      <value>gr.GR_COS_WAVE</value>
+    </param>
+    <param>
+      <key>freq</key>
+      <value>freq</value>
+    </param>
+    <param>
+      <key>amp</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>offset</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(203, 8)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blks2_packet_decoder</key>
+    <param>
+      <key>id</key>
+      <value>blks2_packet_decoder_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>access_code</key>
+      <value></value>
+    </param>
+    <param>
+      <key>threshold</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(551, 65)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_scopesink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_scopesink2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Scope Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>frame_decim</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>v_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>t_scale</key>
+      <value>1./freq</value>
+    </param>
+    <param>
+      <key>marker</key>
+      <value>set_format_line</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(769, 12)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blks2_dxpsk_demod</key>
+    <param>
+      <key>id</key>
+      <value>blks2_dxpsk_demod_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>dbpsk</value>
+    </param>
+    <param>
+      <key>samples_per_symbol</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>excess_bw</key>
+      <value>0.35</value>
+    </param>
+    <param>
+      <key>costas_alpha</key>
+      <value>0.175</value>
+    </param>
+    <param>
+      <key>gain_mu</key>
+      <value>0.175</value>
+    </param>
+    <param>
+      <key>mu</key>
+      <value>0.5</value>
+    </param>
+    <param>
+      <key>omega_relative_limit</key>
+      <value>0.005</value>
+    </param>
+    <param>
+      <key>gray_code</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(691, 219)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>blks2_dxpsk_mod_0</source_block_id>
+    <sink_block_id>blks2_dxpsk_demod_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blks2_dxpsk_demod_0</source_block_id>
+    <sink_block_id>blks2_packet_decoder_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blks2_packet_encoder_0</source_block_id>
+    <sink_block_id>blks2_dxpsk_mod_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_sig_source_x_0</source_block_id>
+    <sink_block_id>gr_throttle_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_throttle_0_0</source_block_id>
+    <sink_block_id>blks2_packet_encoder_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blks2_packet_decoder_0</source_block_id>
+    <sink_block_id>wxgui_scopesink2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gnuradio-examples/grc/simple/var_sink_taps.grc b/gnuradio-examples/grc/simple/var_sink_taps.grc
new file mode 100644
index 000000000..07207850e
--- /dev/null
+++ b/gnuradio-examples/grc/simple/var_sink_taps.grc
@@ -0,0 +1,488 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Tue May 19 16:45:51 2009</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>var_sink_taps</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Variable Sink + Taps</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value>Example</value>
+    </param>
+    <param>
+      <key>description</key>
+      <value>gnuradio flow graph</value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_noise_source_x</key>
+    <param>
+      <key>id</key>
+      <value>gr_noise_source_x_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>noise_type</key>
+      <value>gr.GR_GAUSSIAN</value>
+    </param>
+    <param>
+      <key>amp</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>seed</key>
+      <value>42</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(619, 36)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_fir_filter_xxx</key>
+    <param>
+      <key>id</key>
+      <value>gr_fir_filter_xxx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ccc</value>
+    </param>
+    <param>
+      <key>decim</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>dest_taps</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(831, 47)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_throttle</key>
+    <param>
+      <key>id</key>
+      <value>gr_throttle_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>samples_per_second</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(999, 198)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>270</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_fftsink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_fftsink2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>FFT Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>baseband_freq</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>y_per_div</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>y_divs</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>fft_size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>fft_rate</key>
+      <value>30</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(629, 184)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>import</key>
+    <param>
+      <key>id</key>
+      <value>import_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>import</key>
+      <value>from gnuradio.gr import firdes</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(330, 120)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>dest_taps</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>[0]</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(836, 223)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(831, 130)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>source_taps</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>firdes.low_pass(1, samp_rate, 4000, 2000)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(397, 191)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>taps_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(268, 189)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_vector_source_x</key>
+    <param>
+      <key>id</key>
+      <value>gr_vector_source_x_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>vector</key>
+      <value>source_taps</value>
+    </param>
+    <param>
+      <key>repeat</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>len(source_taps)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(205, 33)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>note</key>
+    <param>
+      <key>id</key>
+      <value>note_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>note</key>
+      <value>Pass the FIR taps via a variable sink.</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(14, 141)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_throttle</key>
+    <param>
+      <key>id</key>
+      <value>gr_throttle</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>samples_per_second</key>
+      <value>taps_rate</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>len(source_taps)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(440, 41)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blks2_variable_sink_x</key>
+    <param>
+      <key>id</key>
+      <value>blks2_variable_sink_x_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>variable</key>
+      <value>dest_taps</value>
+    </param>
+    <param>
+      <key>decim</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>len(source_taps)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(305, 283)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>gr_noise_source_x_0</source_block_id>
+    <sink_block_id>gr_fir_filter_xxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_fir_filter_xxx_0</source_block_id>
+    <sink_block_id>gr_throttle_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_throttle_0</source_block_id>
+    <sink_block_id>wxgui_fftsink2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_vector_source_x_0</source_block_id>
+    <sink_block_id>gr_throttle</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_throttle</source_block_id>
+    <sink_block_id>blks2_variable_sink_x_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gnuradio-examples/grc/simple/variable_config.grc b/gnuradio-examples/grc/simple/variable_config.grc
new file mode 100644
index 000000000..95c287cce
--- /dev/null
+++ b/gnuradio-examples/grc/simple/variable_config.grc
@@ -0,0 +1,329 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Thu Jun 25 10:56:04 2009</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>variable_config_demo</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Variable Config Block Demonstration</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value>Example</value>
+    </param>
+    <param>
+      <key>description</key>
+      <value>Save/Load freq from a config file.</value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>autostart</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 170)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_config</key>
+    <param>
+      <key>id</key>
+      <value>freq_init</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>real</value>
+    </param>
+    <param>
+      <key>config_file</key>
+      <value>config.conf</value>
+    </param>
+    <param>
+      <key>section</key>
+      <value>main</value>
+    </param>
+    <param>
+      <key>option</key>
+      <value>freq</value>
+    </param>
+    <param>
+      <key>writeback</key>
+      <value>freq</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(255, 17)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>freq</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Frequency (Hz)</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>freq_init</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>-samp_rate/2</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>samp_rate/2</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(429, 24)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_throttle</key>
+    <param>
+      <key>id</key>
+      <value>gr_throttle_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>samples_per_second</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(392, 233)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_sig_source_x</key>
+    <param>
+      <key>id</key>
+      <value>gr_sig_source_x_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>waveform</key>
+      <value>gr.GR_COS_WAVE</value>
+    </param>
+    <param>
+      <key>freq</key>
+      <value>freq</value>
+    </param>
+    <param>
+      <key>amp</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>offset</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(148, 233)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_fftsink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_fftsink2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>FFT Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>baseband_freq</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>y_per_div</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>y_divs</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>fft_size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>fft_rate</key>
+      <value>30</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(671, 233)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>gr_sig_source_x_0</source_block_id>
+    <sink_block_id>gr_throttle_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_throttle_0</source_block_id>
+    <sink_block_id>wxgui_fftsink2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gnuradio-examples/grc/trellis/interference_cancellation.grc b/gnuradio-examples/grc/trellis/interference_cancellation.grc
new file mode 100644
index 000000000..e93babd78
--- /dev/null
+++ b/gnuradio-examples/grc/trellis/interference_cancellation.grc
@@ -0,0 +1,2072 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Thu Mar 19 11:22:40 2009</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>int_cancellation</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Superposition Coding</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value>AA</value>
+    </param>
+    <param>
+      <key>description</key>
+      <value>gnuradio flow graph</value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>2048, 2048</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>alpha</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>P1/P</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.6</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>slider_length</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>slider_type</key>
+      <value>horizontal</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(243, 11)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>snr_db</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>P/sigma^2 (dB)</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>16</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>20</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>slider_length</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>slider_type</key>
+      <value>horizontal</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(447, 14)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>noisevar</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>10**(-snr_db/10)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(637, 13)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>random_source_x</key>
+    <param>
+      <key>id</key>
+      <value>random_source_x_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>short</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>num_samps</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>repeat</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(21, 170)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_chunks_to_symbols_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_chunks_to_symbols_xx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>short</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>1,1j,-1j,-1</value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(665, 187)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_multiply_const_vxx</key>
+    <param>
+      <key>id</key>
+      <value>gr_multiply_const_vxx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>alpha**0.5</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(988, 196)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>random_source_x</key>
+    <param>
+      <key>id</key>
+      <value>random_source_x_1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>short</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>num_samps</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>repeat</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(25, 291)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_chunks_to_symbols_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_chunks_to_symbols_xx_1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>short</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>1,1j,-1j,-1</value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(660, 311)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_multiply_const_vxx</key>
+    <param>
+      <key>id</key>
+      <value>gr_multiply_const_vxx_1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>(1-alpha)**0.5</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(994, 319)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_add_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_add_xx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1224, 244)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_noise_source_x</key>
+    <param>
+      <key>id</key>
+      <value>gr_noise_source_x_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>noise_type</key>
+      <value>gr.GR_GAUSSIAN</value>
+    </param>
+    <param>
+      <key>amp</key>
+      <value>noisevar</value>
+    </param>
+    <param>
+      <key>seed</key>
+      <value>42</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1146, 369)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_sub_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_sub_xx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>short</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(536, 529)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_multiply_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_multiply_xx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>short</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(771, 525)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_short_to_float</key>
+    <param>
+      <key>id</key>
+      <value>gr_short_to_float_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(994, 545)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_sub_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_sub_xx_3</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>short</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(535, 792)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_multiply_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_multiply_xx_1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>short</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(785, 779)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_short_to_float</key>
+    <param>
+      <key>id</key>
+      <value>gr_short_to_float_2</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1005, 798)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_chunks_to_symbols_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_chunks_to_symbols_xx_2</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>short</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>1,1j,-1j,-1</value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(405, 998)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_multiply_const_vxx</key>
+    <param>
+      <key>id</key>
+      <value>gr_multiply_const_vxx_2</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>alpha**0.5</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(710, 1008)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_sub_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_sub_xx_2</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(944, 978)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_sub_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_sub_xx_1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>short</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(540, 1141)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_multiply_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_multiply_xx_2</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>short</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(796, 1136)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_short_to_float</key>
+    <param>
+      <key>id</key>
+      <value>gr_short_to_float_1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1009, 1156)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_chunks_to_symbols_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_chunks_to_symbols_xx_2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>in_type</key>
+      <value>short</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>symbol_table</key>
+      <value>1,1j,-1j,-1</value>
+    </param>
+    <param>
+      <key>dimension</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(420, 1368)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_multiply_const_vxx</key>
+    <param>
+      <key>id</key>
+      <value>gr_multiply_const_vxx_2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>(1-alpha)**0.5</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(733, 1374)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_sub_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_sub_xx_2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(975, 1342)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_sub_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_sub_xx_1_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>short</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(559, 1536)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_multiply_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_multiply_xx_2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>short</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(771, 1530)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_short_to_float</key>
+    <param>
+      <key>id</key>
+      <value>gr_short_to_float_1_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1010, 1551)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_numbersink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_numbersink2_2</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>BER 2 (raw)</value>
+    </param>
+    <param>
+      <key>units</key>
+      <value>BER</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>R</value>
+    </param>
+    <param>
+      <key>base_value</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>min_value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max_value</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>factor</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>decimal_places</key>
+      <value>6</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>number_rate</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0.001</value>
+    </param>
+    <param>
+      <key>show_gauge</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>0,1,1,1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1260, 659)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_numbersink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_numbersink2_3</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>BER 2 (after cancelling user 1)</value>
+    </param>
+    <param>
+      <key>units</key>
+      <value>BER</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>R</value>
+    </param>
+    <param>
+      <key>base_value</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>min_value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max_value</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>factor</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>decimal_places</key>
+      <value>6</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>number_rate</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0.001</value>
+    </param>
+    <param>
+      <key>show_gauge</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>1,1,1,1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1262, 1020)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_numbersink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_numbersink2_3_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>BER 1 (after cancelling user 2)</value>
+    </param>
+    <param>
+      <key>units</key>
+      <value>BER</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>R</value>
+    </param>
+    <param>
+      <key>base_value</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>min_value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max_value</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>factor</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>decimal_places</key>
+      <value>6</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>number_rate</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0.001</value>
+    </param>
+    <param>
+      <key>show_gauge</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>1,0,1,1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1269, 1417)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>R</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>10e3</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(748, 12)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>trellis_encoder_xx</key>
+    <param>
+      <key>id</key>
+      <value>trellis_encoder_xx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ss</value>
+    </param>
+    <param>
+      <key>fsm_args</key>
+      <value>prefix+"gr-trellis/src/examples/fsm_files/awgn1o2_16.fsm"</value>
+    </param>
+    <param>
+      <key>init_state</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(334, 190)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>trellis_encoder_xx</key>
+    <param>
+      <key>id</key>
+      <value>trellis_encoder_xx_1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ss</value>
+    </param>
+    <param>
+      <key>fsm_args</key>
+      <value>prefix+"gr-trellis/src/examples/fsm_files/awgn1o2_16.fsm"</value>
+    </param>
+    <param>
+      <key>init_state</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(336, 311)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>trellis_viterbi_combined_xx</key>
+    <param>
+      <key>id</key>
+      <value>trellis_viterbi_combined_xx_1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>c</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>s</value>
+    </param>
+    <param>
+      <key>fsm_args</key>
+      <value>prefix+"gr-trellis/src/examples/fsm_files/awgn1o2_16.fsm"</value>
+    </param>
+    <param>
+      <key>block_size</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>init_state</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>final_state</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>dim</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>table</key>
+      <value>alpha**0.5*1,alpha**0.5*1j,alpha**0.5*(-1j),alpha**0.5*(-1)</value>
+    </param>
+    <param>
+      <key>metric_type</key>
+      <value>trellis.TRELLIS_EUCLIDEAN</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(79, 501)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>trellis_viterbi_combined_xx</key>
+    <param>
+      <key>id</key>
+      <value>trellis_viterbi_combined_xx_2</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>c</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>s</value>
+    </param>
+    <param>
+      <key>fsm_args</key>
+      <value>prefix+"gr-trellis/src/examples/fsm_files/awgn1o2_16.fsm"</value>
+    </param>
+    <param>
+      <key>block_size</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>init_state</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>final_state</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>dim</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>table</key>
+      <value>(1-alpha)**0.5*1,(1-alpha)**0.5*1j,(1-alpha)**0.5*(-1j),(1-alpha)**0.5*(-1)</value>
+    </param>
+    <param>
+      <key>metric_type</key>
+      <value>trellis.TRELLIS_EUCLIDEAN</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(82, 766)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>trellis_encoder_xx</key>
+    <param>
+      <key>id</key>
+      <value>trellis_encoder_xx_2</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ss</value>
+    </param>
+    <param>
+      <key>fsm_args</key>
+      <value>prefix+"gr-trellis/src/examples/fsm_files/awgn1o2_16.fsm"</value>
+    </param>
+    <param>
+      <key>init_state</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(89, 998)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>trellis_viterbi_combined_xx</key>
+    <param>
+      <key>id</key>
+      <value>trellis_viterbi_combined_xx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>c</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>s</value>
+    </param>
+    <param>
+      <key>fsm_args</key>
+      <value>prefix+"gr-trellis/src/examples/fsm_files/awgn1o2_16.fsm"</value>
+    </param>
+    <param>
+      <key>block_size</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>init_state</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>final_state</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>dim</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>table</key>
+      <value>(1-alpha)**0.5*1,(1-alpha)**0.5*1j,(1-alpha)**0.5*(-1j),(1-alpha)**0.5*(-1)</value>
+    </param>
+    <param>
+      <key>metric_type</key>
+      <value>trellis.TRELLIS_EUCLIDEAN</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(83, 1111)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>trellis_encoder_xx</key>
+    <param>
+      <key>id</key>
+      <value>trellis_encoder_xx_2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>ss</value>
+    </param>
+    <param>
+      <key>fsm_args</key>
+      <value>prefix+"gr-trellis/src/examples/fsm_files/awgn1o2_16.fsm"</value>
+    </param>
+    <param>
+      <key>init_state</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(105, 1367)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>trellis_viterbi_combined_xx</key>
+    <param>
+      <key>id</key>
+      <value>trellis_viterbi_combined_xx_0_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>c</value>
+    </param>
+    <param>
+      <key>out_type</key>
+      <value>s</value>
+    </param>
+    <param>
+      <key>fsm_args</key>
+      <value>prefix+"gr-trellis/src/examples/fsm_files/awgn1o2_16.fsm"</value>
+    </param>
+    <param>
+      <key>block_size</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>init_state</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>final_state</key>
+      <value>-1</value>
+    </param>
+    <param>
+      <key>dim</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>table</key>
+      <value>alpha**0.5*1,alpha**0.5*1j,alpha**0.5*(-1j),alpha**0.5*(-1)</value>
+    </param>
+    <param>
+      <key>metric_type</key>
+      <value>trellis.TRELLIS_EUCLIDEAN</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(75, 1495)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>prefix</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>"../../../"</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(871, 14)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_add_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_add_xx_1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1400, 262)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_numbersink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_numbersink2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>BER 1 (raw)</value>
+    </param>
+    <param>
+      <key>units</key>
+      <value>BER</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>R</value>
+    </param>
+    <param>
+      <key>base_value</key>
+      <value>0.0</value>
+    </param>
+    <param>
+      <key>min_value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max_value</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>factor</key>
+      <value>1.0</value>
+    </param>
+    <param>
+      <key>decimal_places</key>
+      <value>6</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>number_rate</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0.001</value>
+    </param>
+    <param>
+      <key>show_gauge</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>0,0,1,1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1267, 410)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_scopesink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_scopesink2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Scope Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>R</value>
+    </param>
+    <param>
+      <key>v_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>t_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>ac_couple</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>xy_mode</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1533, 149)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>random_source_x_1</source_block_id>
+    <sink_block_id>trellis_encoder_xx_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>trellis_encoder_xx_0</source_block_id>
+    <sink_block_id>gr_chunks_to_symbols_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>trellis_encoder_xx_1</source_block_id>
+    <sink_block_id>gr_chunks_to_symbols_xx_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_chunks_to_symbols_xx_0</source_block_id>
+    <sink_block_id>gr_multiply_const_vxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>gr_add_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_add_xx_0</source_block_id>
+    <sink_block_id>gr_add_xx_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_noise_source_x_0</source_block_id>
+    <sink_block_id>gr_add_xx_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_chunks_to_symbols_xx_1</source_block_id>
+    <sink_block_id>gr_multiply_const_vxx_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_multiply_const_vxx_1</source_block_id>
+    <sink_block_id>gr_add_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_sub_xx_0</source_block_id>
+    <sink_block_id>gr_multiply_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_sub_xx_0</source_block_id>
+    <sink_block_id>gr_multiply_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_multiply_xx_0</source_block_id>
+    <sink_block_id>gr_short_to_float_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_short_to_float_0</source_block_id>
+    <sink_block_id>wxgui_numbersink2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_multiply_xx_2</source_block_id>
+    <sink_block_id>gr_short_to_float_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>random_source_x_0</source_block_id>
+    <sink_block_id>trellis_encoder_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_add_xx_1</source_block_id>
+    <sink_block_id>trellis_viterbi_combined_xx_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>random_source_x_0</source_block_id>
+    <sink_block_id>gr_sub_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>trellis_viterbi_combined_xx_1</source_block_id>
+    <sink_block_id>gr_sub_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>trellis_viterbi_combined_xx_0</source_block_id>
+    <sink_block_id>gr_sub_xx_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>random_source_x_1</source_block_id>
+    <sink_block_id>gr_sub_xx_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_sub_xx_1</source_block_id>
+    <sink_block_id>gr_multiply_xx_2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_sub_xx_1</source_block_id>
+    <sink_block_id>gr_multiply_xx_2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_sub_xx_2</source_block_id>
+    <sink_block_id>trellis_viterbi_combined_xx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_add_xx_1</source_block_id>
+    <sink_block_id>gr_sub_xx_2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>trellis_encoder_xx_2</source_block_id>
+    <sink_block_id>gr_chunks_to_symbols_xx_2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_chunks_to_symbols_xx_2</source_block_id>
+    <sink_block_id>gr_multiply_const_vxx_2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_multiply_const_vxx_2</source_block_id>
+    <sink_block_id>gr_sub_xx_2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>trellis_viterbi_combined_xx_1</source_block_id>
+    <sink_block_id>trellis_encoder_xx_2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_multiply_xx_1</source_block_id>
+    <sink_block_id>gr_short_to_float_2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_short_to_float_2</source_block_id>
+    <sink_block_id>wxgui_numbersink2_2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>trellis_viterbi_combined_xx_2</source_block_id>
+    <sink_block_id>gr_sub_xx_3</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_sub_xx_3</source_block_id>
+    <sink_block_id>gr_multiply_xx_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_sub_xx_3</source_block_id>
+    <sink_block_id>gr_multiply_xx_1</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_add_xx_1</source_block_id>
+    <sink_block_id>trellis_viterbi_combined_xx_2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>random_source_x_1</source_block_id>
+    <sink_block_id>gr_sub_xx_3</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_short_to_float_1</source_block_id>
+    <sink_block_id>wxgui_numbersink2_3</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>trellis_encoder_xx_2_0</source_block_id>
+    <sink_block_id>gr_chunks_to_symbols_xx_2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_chunks_to_symbols_xx_2_0</source_block_id>
+    <sink_block_id>gr_multiply_const_vxx_2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>trellis_viterbi_combined_xx_2</source_block_id>
+    <sink_block_id>trellis_encoder_xx_2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_multiply_xx_2_0</source_block_id>
+    <sink_block_id>gr_short_to_float_1_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>trellis_viterbi_combined_xx_0_0</source_block_id>
+    <sink_block_id>gr_sub_xx_1_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_sub_xx_1_0</source_block_id>
+    <sink_block_id>gr_multiply_xx_2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_sub_xx_1_0</source_block_id>
+    <sink_block_id>gr_multiply_xx_2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_sub_xx_2_0</source_block_id>
+    <sink_block_id>trellis_viterbi_combined_xx_0_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_short_to_float_1_0</source_block_id>
+    <sink_block_id>wxgui_numbersink2_3_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_add_xx_1</source_block_id>
+    <sink_block_id>gr_sub_xx_2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>random_source_x_0</source_block_id>
+    <sink_block_id>gr_sub_xx_1_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_multiply_const_vxx_2_0</source_block_id>
+    <sink_block_id>gr_sub_xx_2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_add_xx_1</source_block_id>
+    <sink_block_id>wxgui_scopesink2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gnuradio-examples/grc/trellis/readme.txt b/gnuradio-examples/grc/trellis/readme.txt
new file mode 100644
index 000000000..d620fd628
--- /dev/null
+++ b/gnuradio-examples/grc/trellis/readme.txt
@@ -0,0 +1,16 @@
+This is an example of using gr-trellis in grc.
+
+Two users are transmitting simultaneously using convolutionally encoded QPSK, each with power P1=alpha*P and P2=(1-alpha)*P.
+The combined signal is observed in noise and four different receivers are considered:
+1) A viterbi decoder decoding user 1 assuming user 2 is noise
+2) A viterbi decoder decoding user 2 assuming user 1 is noise
+3) A viterbi decoder decoding user 1 first 
+   and then reencoding this signal, subtracting it from the observation 
+   and then running a Viterbi decoder decoding user 2
+4) A viterbi decoder decoding user 2 first 
+   and then reencoding this signal, subtracting it from the observation 
+   and then running a Viterbi decoder decoding user 1
+
+You can change the signal to noise ratio P/sigma^2 and the allocation of power to the two users, alpha.
+
+Enjoy.
diff --git a/gnuradio-examples/grc/usrp/usrp2_const_wave.grc b/gnuradio-examples/grc/usrp/usrp2_const_wave.grc
new file mode 100644
index 000000000..fdbd7c1f3
--- /dev/null
+++ b/gnuradio-examples/grc/usrp/usrp2_const_wave.grc
@@ -0,0 +1,252 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Wed Apr 15 11:22:56 2009</timestamp>
+  <block>
+    <key>const_source_x</key>
+    <param>
+      <key>id</key>
+      <value>const_source_x_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>ampl</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(284, 154)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>usrp2_sink_xxxx</key>
+    <param>
+      <key>id</key>
+      <value>usrp2_sink_xxxx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>interface</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mac_addr</key>
+      <value></value>
+    </param>
+    <param>
+      <key>interpolation</key>
+      <value>interp</value>
+    </param>
+    <param>
+      <key>frequency</key>
+      <value>tun_freq</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(493, 106)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>interp</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>16</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(16, 255)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>tun_freq</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>USRP2 Freq (Hz)</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2.45e9</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>2.4e9</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>2.5e9</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>slider_length</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>slider_type</key>
+      <value>horizontal</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(30, 376)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>ampl</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>.1</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>slider_length</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>slider_type</key>
+      <value>horizontal</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(204, 376)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>usrp2_const_wave</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>USRP2 Constant Wave</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value>Example</value>
+    </param>
+    <param>
+      <key>description</key>
+      <value>Tune USRP2</value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>const_source_x_0</source_block_id>
+    <sink_block_id>usrp2_sink_xxxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gnuradio-examples/grc/usrp/usrp2_dpsk_mod.grc b/gnuradio-examples/grc/usrp/usrp2_dpsk_mod.grc
new file mode 100644
index 000000000..e9f9b41ea
--- /dev/null
+++ b/gnuradio-examples/grc/usrp/usrp2_dpsk_mod.grc
@@ -0,0 +1,693 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Wed Apr 15 17:31:00 2009</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>usrp2_dpsk_mod</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>USRP2 DPSK Modulation</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value>Example</value>
+    </param>
+    <param>
+      <key>description</key>
+      <value>Generate a DPSK signal</value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>100e6/interp</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(52, 166)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>usrp2_sink_xxxx</key>
+    <param>
+      <key>id</key>
+      <value>usrp2_sink_xxxx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>interface</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mac_addr</key>
+      <value></value>
+    </param>
+    <param>
+      <key>interpolation</key>
+      <value>interp</value>
+    </param>
+    <param>
+      <key>frequency</key>
+      <value>tun_freq</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(1059, 56)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_multiply_const_vxx</key>
+    <param>
+      <key>id</key>
+      <value>gr_multiply_const_vxx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>ampl</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(679, 58)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blks2_dxpsk_mod</key>
+    <param>
+      <key>id</key>
+      <value>blks2_dxpsk_mod_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>dqpsk</value>
+    </param>
+    <param>
+      <key>samples_per_symbol</key>
+      <value>samps_per_sym</value>
+    </param>
+    <param>
+      <key>excess_bw</key>
+      <value>0.35</value>
+    </param>
+    <param>
+      <key>gray_code</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(468, 55)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>interp</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(31, 256)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>samps_per_sym</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(126, 250)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>random_source_x</key>
+    <param>
+      <key>id</key>
+      <value>random_source_x_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>byte</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>256</value>
+    </param>
+    <param>
+      <key>num_samps</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>repeat</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(255, 39)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>ampl</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>.1</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(246, 372)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>rx_freq_off</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>RX Freq Offset (Hz)</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>-20e3</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>-50e3</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>+50e3</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(247, 508)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>tun_freq</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>USRP2 Freq (Hz)</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2.45e9</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>2.4e9</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>2.5e9</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(49, 341)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_constellationsink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_constellationsink2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Constellation Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>frame_rate</key>
+      <value>5</value>
+    </param>
+    <param>
+      <key>const_size</key>
+      <value>2048</value>
+    </param>
+    <param>
+      <key>M</key>
+      <value>4</value>
+    </param>
+    <param>
+      <key>theta</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>alpha</key>
+      <value>0.005</value>
+    </param>
+    <param>
+      <key>fmax</key>
+      <value>0.06</value>
+    </param>
+    <param>
+      <key>mu</key>
+      <value>0.5</value>
+    </param>
+    <param>
+      <key>gain_mu</key>
+      <value>0.005</value>
+    </param>
+    <param>
+      <key>symbol_rate</key>
+      <value>samp_rate/samps_per_sym</value>
+    </param>
+    <param>
+      <key>omega_limit</key>
+      <value>0.005</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(920, 202)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_fftsink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_fftsink2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>FFT Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>baseband_freq</key>
+      <value>tun_freq</value>
+    </param>
+    <param>
+      <key>y_per_div</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>fft_size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>fft_rate</key>
+      <value>30</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(691, 155)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_scopesink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_scopesink2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Scope Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>v_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>t_scale</key>
+      <value>1e-6</value>
+    </param>
+    <param>
+      <key>ac_couple</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>xy_mode</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(515, 272)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>usrp2_source_xxxx</key>
+    <param>
+      <key>id</key>
+      <value>usrp2_source_xxxx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>interface</key>
+      <value>eth1</value>
+    </param>
+    <param>
+      <key>mac_addr</key>
+      <value></value>
+    </param>
+    <param>
+      <key>decimation</key>
+      <value>interp</value>
+    </param>
+    <param>
+      <key>frequency</key>
+      <value>tun_freq + rx_freq_off</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>30</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(270, 200)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>random_source_x_0</source_block_id>
+    <sink_block_id>blks2_dxpsk_mod_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blks2_dxpsk_mod_0</source_block_id>
+    <sink_block_id>gr_multiply_const_vxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_multiply_const_vxx_0</source_block_id>
+    <sink_block_id>usrp2_sink_xxxx_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>usrp2_source_xxxx_0</source_block_id>
+    <sink_block_id>wxgui_constellationsink2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>usrp2_source_xxxx_0</source_block_id>
+    <sink_block_id>wxgui_scopesink2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>usrp2_source_xxxx_0</source_block_id>
+    <sink_block_id>wxgui_fftsink2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gnuradio-examples/grc/usrp/usrp2_fft.grc b/gnuradio-examples/grc/usrp/usrp2_fft.grc
new file mode 100644
index 000000000..134bd4614
--- /dev/null
+++ b/gnuradio-examples/grc/usrp/usrp2_fft.grc
@@ -0,0 +1,264 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Wed Apr 15 17:30:20 2009</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>usrp2_fft</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>USRP2 FFT Plotter</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value>Example</value>
+    </param>
+    <param>
+      <key>description</key>
+      <value>FFT waveform plot</value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>100e6/decim</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 170)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>decim</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>16</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(24, 267)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>tun_freq</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>USRP2 Freq (Hz)</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2.45e9</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>2.4e9</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>2.5e9</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(32, 365)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_fftsink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_fftsink2_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>FFT Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>baseband_freq</key>
+      <value>tun_freq</value>
+    </param>
+    <param>
+      <key>y_per_div</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>fft_size</key>
+      <value>1024</value>
+    </param>
+    <param>
+      <key>fft_rate</key>
+      <value>30</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(466, 100)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>usrp2_source_xxxx</key>
+    <param>
+      <key>id</key>
+      <value>usrp2_source_xxxx_0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>interface</key>
+      <value></value>
+    </param>
+    <param>
+      <key>mac_addr</key>
+      <value></value>
+    </param>
+    <param>
+      <key>decimation</key>
+      <value>decim</value>
+    </param>
+    <param>
+      <key>frequency</key>
+      <value>tun_freq</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(211, 200)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>usrp2_source_xxxx_0</source_block_id>
+    <sink_block_id>wxgui_fftsink2_0</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gnuradio-examples/grc/usrp/usrp_two_tone_loopback.grc b/gnuradio-examples/grc/usrp/usrp_two_tone_loopback.grc
new file mode 100644
index 000000000..3df977044
--- /dev/null
+++ b/gnuradio-examples/grc/usrp/usrp_two_tone_loopback.grc
@@ -0,0 +1,749 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Fri Apr 17 18:23:35 2009</timestamp>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>64e6/200</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(9, 166)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>tun_freq</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>int(100e6)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(116, 166)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_sig_source_x</key>
+    <param>
+      <key>id</key>
+      <value>gr_sig_source_x</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>waveform</key>
+      <value>gr.GR_COS_WAVE</value>
+    </param>
+    <param>
+      <key>freq</key>
+      <value>tone1</value>
+    </param>
+    <param>
+      <key>amp</key>
+      <value>tone_ampl</value>
+    </param>
+    <param>
+      <key>offset</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(258, 20)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_sig_source_x</key>
+    <param>
+      <key>id</key>
+      <value>gr_sig_source_x0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>waveform</key>
+      <value>gr.GR_COS_WAVE</value>
+    </param>
+    <param>
+      <key>freq</key>
+      <value>tone2</value>
+    </param>
+    <param>
+      <key>amp</key>
+      <value>tone_ampl</value>
+    </param>
+    <param>
+      <key>offset</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(255, 179)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_add_xx</key>
+    <param>
+      <key>id</key>
+      <value>gr_add_xx</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>3</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(528, 78)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>id</key>
+      <value>tx_side</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>A</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>string</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(688, 384)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>usrp_simple_sink_x</key>
+    <param>
+      <key>id</key>
+      <value>usrp_simple_sink_x</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value></value>
+    </param>
+    <param>
+      <key>which</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>interpolation</key>
+      <value>400</value>
+    </param>
+    <param>
+      <key>frequency</key>
+      <value>tun_freq</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>side</key>
+      <value>tx_side</value>
+    </param>
+    <param>
+      <key>transmit</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(835, 5)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>usrp_simple_source_x</key>
+    <param>
+      <key>id</key>
+      <value>usrp_simple_source_x</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value></value>
+    </param>
+    <param>
+      <key>which</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>decimation</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>frequency</key>
+      <value>tun_freq</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>20</value>
+    </param>
+    <param>
+      <key>side</key>
+      <value>rx_side</value>
+    </param>
+    <param>
+      <key>rx_ant</key>
+      <value>rx_ant</value>
+    </param>
+    <param>
+      <key>hb_filters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(479, 224)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>id</key>
+      <value>rx_ant</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>RXA</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>string</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(802, 384)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_fftsink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_fftsink2</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>FFT Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>baseband_freq</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>y_per_div</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>fft_size</key>
+      <value>512*2</value>
+    </param>
+    <param>
+      <key>fft_rate</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>1, 2, 2, 4</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(746, 133)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>parameter</key>
+    <param>
+      <key>id</key>
+      <value>rx_side</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value></value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>A</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>string</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(568, 382)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_noise_source_x</key>
+    <param>
+      <key>id</key>
+      <value>gr_noise_source_x</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>noise_type</key>
+      <value>gr.GR_GAUSSIAN</value>
+    </param>
+    <param>
+      <key>amp</key>
+      <value>noise_ampl</value>
+    </param>
+    <param>
+      <key>seed</key>
+      <value>42</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(276, 312)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>noise_ampl</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Noise Ampl</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>2000</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>5000</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_VERTICAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>1, 1, 2, 1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(20, 243)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>tone_ampl</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Tone Ampl</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>5000</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>10e3</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_VERTICAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>1, 0, 2, 1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(28, 437)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>tone1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Tone 1</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>50e3</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>-samp_rate/2</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>samp_rate/2</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>0, 0, 1, 4</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(190, 436)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>tone2</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Tone 2</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>75e3</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>-samp_rate/2</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>samp_rate/2</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>0, 4, 1, 4</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(367, 439)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>usrp_two_tone_loopback</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>USRP Loopback - 2 Tone</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value>Example</value>
+    </param>
+    <param>
+      <key>description</key>
+      <value>Loopback test with basic rx and basic tx</value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>gr_sig_source_x</source_block_id>
+    <sink_block_id>gr_add_xx</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_sig_source_x0</source_block_id>
+    <sink_block_id>gr_add_xx</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>1</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_noise_source_x</source_block_id>
+    <sink_block_id>gr_add_xx</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>2</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>usrp_simple_source_x</source_block_id>
+    <sink_block_id>wxgui_fftsink2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_add_xx</source_block_id>
+    <sink_block_id>usrp_simple_sink_x</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gnuradio-examples/grc/usrp/usrp_wbfm_receive.grc b/gnuradio-examples/grc/usrp/usrp_wbfm_receive.grc
new file mode 100644
index 000000000..8f53475ab
--- /dev/null
+++ b/gnuradio-examples/grc/usrp/usrp_wbfm_receive.grc
@@ -0,0 +1,466 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Fri Apr 17 19:06:07 2009</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>usrp_wbfm_receive</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>USRP WBFM Receive</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value>Example</value>
+    </param>
+    <param>
+      <key>description</key>
+      <value>WBFM Receive with Basic RX or TV RX</value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>realtime_scheduling</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>decim</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>200</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(14, 173)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>volume</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Volume</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>1, 0, 1, 4</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(991, 40)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>usrp_simple_source_x</key>
+    <param>
+      <key>id</key>
+      <value>usrp_simple_source_x</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>format</key>
+      <value></value>
+    </param>
+    <param>
+      <key>which</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>decimation</key>
+      <value>decim</value>
+    </param>
+    <param>
+      <key>frequency</key>
+      <value>(freq+fine)*1e6</value>
+    </param>
+    <param>
+      <key>gain</key>
+      <value>20</value>
+    </param>
+    <param>
+      <key>side</key>
+      <value>A</value>
+    </param>
+    <param>
+      <key>rx_ant</key>
+      <value>None</value>
+    </param>
+    <param>
+      <key>hb_filters</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(277, 29)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_fftsink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_fftsink2</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>FFT Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>64e6/decim</value>
+    </param>
+    <param>
+      <key>baseband_freq</key>
+      <value>(freq+fine)*1e6</value>
+    </param>
+    <param>
+      <key>y_per_div</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>fft_size</key>
+      <value>512</value>
+    </param>
+    <param>
+      <key>fft_rate</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>2, 0, 2, 4</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(512, 191)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>freq</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Frequency (MHz)</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>87.5</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>108.0</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>0, 0, 1, 2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(104, 243)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>fine</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Fine Freq (MHz)</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>-.1</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>.1</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>style</key>
+      <value>wx.SL_HORIZONTAL</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>0, 2, 1, 2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(275, 246)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blks2_wfm_rcv</key>
+    <param>
+      <key>id</key>
+      <value>blks2_wfm_rcv</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>quad_rate</key>
+      <value>64e6/decim</value>
+    </param>
+    <param>
+      <key>audio_decimation</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(510, 37)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_multiply_const_vxx</key>
+    <param>
+      <key>id</key>
+      <value>gr_multiply_const_vxx</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>volume</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(764, 55)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>audio_sink</key>
+    <param>
+      <key>id</key>
+      <value>audio_sink</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>32000</value>
+    </param>
+    <param>
+      <key>device_name</key>
+      <value></value>
+    </param>
+    <param>
+      <key>ok_to_block</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(703, 241)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>usrp_simple_source_x</source_block_id>
+    <sink_block_id>blks2_wfm_rcv</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>usrp_simple_source_x</source_block_id>
+    <sink_block_id>wxgui_fftsink2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>blks2_wfm_rcv</source_block_id>
+    <sink_block_id>gr_multiply_const_vxx</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_multiply_const_vxx</source_block_id>
+    <sink_block_id>audio_sink</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gnuradio-examples/grc/xmlrpc/readme.txt b/gnuradio-examples/grc/xmlrpc/readme.txt
new file mode 100644
index 000000000..c1f87c1cb
--- /dev/null
+++ b/gnuradio-examples/grc/xmlrpc/readme.txt
@@ -0,0 +1,18 @@
+##################################################
+# XMLRPC example
+##################################################
+
+XMLRPC allows software to make remote function calls over http. 
+In the case of GRC, one can use XMLRPC to modify variables in a running flow graph.
+See http://www.xmlrpc.com/
+
+--- Server Example ---
+Place an "XMLRPC Server" block inside of any flow graph. 
+The server will provide set functions for every variable in the flow graph.
+If a variable is called "freq", the server will provide a function set_freq(new_freq).
+Run the server example and experiment with the example client script.
+
+-- Client Example --
+The "XMLRPC Client" block will give a variable control over one remove function.
+In the example client, there is one client block and gui control per variable.
+This technique can be used to remotely control a flow graph, perhaps running on a non-gui machine.
diff --git a/gnuradio-examples/grc/xmlrpc/xmlrpc_client.grc b/gnuradio-examples/grc/xmlrpc/xmlrpc_client.grc
new file mode 100644
index 000000000..3bb4e7ed3
--- /dev/null
+++ b/gnuradio-examples/grc/xmlrpc/xmlrpc_client.grc
@@ -0,0 +1,312 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Thu Jul 24 14:27:44 2008</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>client_block</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>XMLRPC Client</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value>Example</value>
+    </param>
+    <param>
+      <key>description</key>
+      <value>example flow graph</value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>xmlrpc_client</key>
+    <param>
+      <key>id</key>
+      <value>xmlrpc_client0</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>addr</key>
+      <value>localhost</value>
+    </param>
+    <param>
+      <key>port</key>
+      <value>1234</value>
+    </param>
+    <param>
+      <key>callback</key>
+      <value>set_ampl</value>
+    </param>
+    <param>
+      <key>variable</key>
+      <value>ampl</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(409, 35)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>xmlrpc_client</key>
+    <param>
+      <key>id</key>
+      <value>xmlrpc_client</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>addr</key>
+      <value>localhost</value>
+    </param>
+    <param>
+      <key>port</key>
+      <value>1234</value>
+    </param>
+    <param>
+      <key>callback</key>
+      <value>set_freq</value>
+    </param>
+    <param>
+      <key>variable</key>
+      <value>freq</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(222, 34)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>freq</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Frequency (Hz)</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>5000</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>slider_type</key>
+      <value>horizontal</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>0, 0, 1, 2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(207, 162)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_slider</key>
+    <param>
+      <key>id</key>
+      <value>ampl</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Amplitude</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>min</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>max</key>
+      <value>2</value>
+    </param>
+    <param>
+      <key>num_steps</key>
+      <value>100</value>
+    </param>
+    <param>
+      <key>slider_type</key>
+      <value>horizontal</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>1, 0, 1, 2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(397, 167)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_chooser</key>
+    <param>
+      <key>id</key>
+      <value>offset</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Offset</value>
+    </param>
+    <param>
+      <key>value_index</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>choices</key>
+      <value>[-1, 0, 1]</value>
+    </param>
+    <param>
+      <key>labels</key>
+      <value>["neg", "zero", "pos"]</value>
+    </param>
+    <param>
+      <key>chooser_type</key>
+      <value>radio_buttons_horizontal</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>2, 0, 1, 2</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(596, 177)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>xmlrpc_client</key>
+    <param>
+      <key>id</key>
+      <value>xmlrpc_client1</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>addr</key>
+      <value>localhost</value>
+    </param>
+    <param>
+      <key>port</key>
+      <value>1234</value>
+    </param>
+    <param>
+      <key>callback</key>
+      <value>set_offset</value>
+    </param>
+    <param>
+      <key>variable</key>
+      <value>offset*ampl</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(608, 39)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(13, 172)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+</flow_graph>
\ No newline at end of file
diff --git a/gnuradio-examples/grc/xmlrpc/xmlrpc_client_script.py b/gnuradio-examples/grc/xmlrpc/xmlrpc_client_script.py
new file mode 100644
index 000000000..956fa07fb
--- /dev/null
+++ b/gnuradio-examples/grc/xmlrpc/xmlrpc_client_script.py
@@ -0,0 +1,23 @@
+#!/usr/bin/env python
+
+import time
+import random
+import xmlrpclib
+
+#create server object
+s = xmlrpclib.Server("http://localhost:1234")
+
+#randomly change parameters of the sinusoid
+for i in range(10):
+	#generate random values
+	new_freq = random.uniform(0, 5000)
+	new_ampl = random.uniform(0, 2)
+	new_offset = random.uniform(-1, 1)
+	#set new values 
+	time.sleep(1)
+	s.set_freq(new_freq)
+	time.sleep(1)
+	s.set_ampl(new_ampl)
+	time.sleep(1)
+	s.set_offset(new_offset)
+
diff --git a/gnuradio-examples/grc/xmlrpc/xmlrpc_server.grc b/gnuradio-examples/grc/xmlrpc/xmlrpc_server.grc
new file mode 100644
index 000000000..dc539ef1b
--- /dev/null
+++ b/gnuradio-examples/grc/xmlrpc/xmlrpc_server.grc
@@ -0,0 +1,384 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Thu Jul 24 14:27:42 2008</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>server_block</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>XMLRPC Server</value>
+    </param>
+    <param>
+      <key>author</key>
+      <value>Example</value>
+    </param>
+    <param>
+      <key>description</key>
+      <value>example flow graph</value>
+    </param>
+    <param>
+      <key>window_size</key>
+      <value>1280, 1024</value>
+    </param>
+    <param>
+      <key>generate_options</key>
+      <value>wx_gui</value>
+    </param>
+    <param>
+      <key>category</key>
+      <value>Custom</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(10, 10)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_sig_source_x</key>
+    <param>
+      <key>id</key>
+      <value>gr_sig_source_x</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>waveform</key>
+      <value>gr.GR_COS_WAVE</value>
+    </param>
+    <param>
+      <key>freq</key>
+      <value>freq</value>
+    </param>
+    <param>
+      <key>amp</key>
+      <value>ampl</value>
+    </param>
+    <param>
+      <key>offset</key>
+      <value>offset</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(162, 200)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>offset</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(12, 390)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>xmlrpc_server</key>
+    <param>
+      <key>id</key>
+      <value>xmlrpc_server</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>addr</key>
+      <value>localhost</value>
+    </param>
+    <param>
+      <key>port</key>
+      <value>1234</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(395, 240)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_throttle</key>
+    <param>
+      <key>id</key>
+      <value>gr_throttle</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>samples_per_second</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(386, 93)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_scopesink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_scopesink2</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Scope Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>frame_decim</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>v_scale</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>t_scale</key>
+      <value>.001</value>
+    </param>
+    <param>
+      <key>marker</key>
+      <value>set_format_line</value>
+    </param>
+    <param>
+      <key>num_inputs</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>0, 0, 2, 4</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(623, 28)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_fftsink2</key>
+    <param>
+      <key>id</key>
+      <value>wxgui_fftsink2</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>FFT Plot</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>baseband_freq</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>y_per_div</key>
+      <value>10</value>
+    </param>
+    <param>
+      <key>y_divs</key>
+      <value>8</value>
+    </param>
+    <param>
+      <key>ref_level</key>
+      <value>50</value>
+    </param>
+    <param>
+      <key>fft_size</key>
+      <value>512</value>
+    </param>
+    <param>
+      <key>fft_rate</key>
+      <value>15</value>
+    </param>
+    <param>
+      <key>avg_alpha</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>average</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>peak_hold</key>
+      <value>False</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>2, 0, 2, 4</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(630, 233)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(11, 160)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>freq</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1000</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(11, 237)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>ampl</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(13, 315)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>gr_sig_source_x</source_block_id>
+    <sink_block_id>gr_throttle</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_throttle</source_block_id>
+    <sink_block_id>wxgui_scopesink2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>gr_throttle</source_block_id>
+    <sink_block_id>wxgui_fftsink2</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
\ No newline at end of file
diff --git a/gnuradio-examples/python/digital/benchmark_qt_loopback.py b/gnuradio-examples/python/digital/benchmark_qt_loopback.py
index e43bffa26..35cc2e376 100755
--- a/gnuradio-examples/python/digital/benchmark_qt_loopback.py
+++ b/gnuradio-examples/python/digital/benchmark_qt_loopback.py
@@ -52,7 +52,7 @@ class dialog_box(QtGui.QMainWindow):
         self.set_frequency(self.fg.frequency_offset())
         self.set_time_offset(self.fg.timing_offset())
 
-        self.set_gain_mu(self.fg.rx_gain_mu())
+        self.set_gain_mu(self.fg.rx_timing_gain_alpha())
         self.set_alpha(self.fg.rx_alpha())
 
         # Add the qtsnk widgets to the hlayout box
@@ -158,7 +158,7 @@ class dialog_box(QtGui.QMainWindow):
     def gainMuEditText(self):
         try:
             gain = self.gui.gainMuEdit.text().toDouble()[0]
-            self.fg.set_rx_gain_mu(gain)
+            self.fg.set_rx_timing_gain_alpha(gain)
         except RuntimeError:
             pass
 
@@ -202,7 +202,7 @@ class my_top_block(gr.top_block):
         self.rxpath = receive_path(demod_class, rx_callback, options)
 
         # FIXME: do better exposure to lower issues for control
-        self._gain_mu = self.rxpath.packet_receiver._demodulator._mm_gain_mu
+        self._timing_gain_alpha = self.rxpath.packet_receiver._demodulator._timing_alpha
         self._alpha = self.rxpath.packet_receiver._demodulator._costas_alpha
 
         if channelon:
@@ -240,16 +240,21 @@ class my_top_block(gr.top_block):
             
                 # Connect to the QT sinks
                 # FIXME: make better exposure to receiver from rxpath
-                self.receiver = self.rxpath.packet_receiver._demodulator.receiver
+                self.freq_recov = self.rxpath.packet_receiver._demodulator.clock_recov
+                self.time_recov = self.rxpath.packet_receiver._demodulator.time_recov
+                self.freq_recov.set_alpha(0)
+                self.freq_recov.set_beta(0)
+                self.time_recov.set_alpha(2)
+                self.time_recov.set_beta(0.02)
                 self.connect(self.channel, self.snk_tx)
-                self.connect(self.receiver, self.snk_rx)
+                self.connect(self.time_recov, self.snk_rx)
 
                 pyTxQt  = self.snk_tx.pyqwidget()
                 pyTx = sip.wrapinstance(pyTxQt, QtGui.QWidget)
-                
+                 
                 pyRxQt  = self.snk_rx.pyqwidget()
                 pyRx = sip.wrapinstance(pyRxQt, QtGui.QWidget)
-                
+
                 self.main_box = dialog_box(pyTx, pyRx, self)
                 self.main_box.show()
                 
@@ -299,17 +304,15 @@ class my_top_block(gr.top_block):
 
 
     # Receiver Parameters
-    def rx_gain_mu(self):
-        return self._gain_mu
+    def rx_timing_gain_alpha(self):
+        return self._timing_gain_alpha
 
-    def rx_gain_omega(self):
-        return self.gain_omega
+    def rx_timing_gain_beta(self):
+        return self._timing_gain_beta
     
-    def set_rx_gain_mu(self, gain):
-        self._gain_mu = gain
-        self.gain_omega = .25 * self._gain_mu * self._gain_mu
-        self.receiver.set_gain_mu(self._gain_mu)
-        self.receiver.set_gain_omega(self.gain_omega)
+    def set_rx_timing_gain_alpha(self, gain):
+        self._timing_gain_alpha = gain
+        self.time_recov.set_gain(self._timing_gain_alpha)
 
     def rx_alpha(self):
         return self._alpha
@@ -320,8 +323,8 @@ class my_top_block(gr.top_block):
     def set_rx_alpha(self, alpha):
         self._alpha = alpha
         self.beta = .25 * self._alpha * self._alpha
-        self.receiver.set_alpha(self._alpha)
-        self.receiver.set_beta(self.beta)
+        #self.freq_recov.set_alpha(self._alpha)
+        #self.freq_recov.set_beta(self.beta)
 
 
 
diff --git a/gnuradio-examples/python/digital/benchmark_qt_loopback2.py b/gnuradio-examples/python/digital/benchmark_qt_loopback2.py
new file mode 100755
index 000000000..101dd68d6
--- /dev/null
+++ b/gnuradio-examples/python/digital/benchmark_qt_loopback2.py
@@ -0,0 +1,488 @@
+#!/usr/bin/env python
+
+from gnuradio import gr, gru, modulation_utils
+from gnuradio import eng_notation
+from gnuradio.eng_option import eng_option
+from optparse import OptionParser
+import random, time, struct, sys, os, math
+
+from threading import Thread
+
+# from current dir
+from transmit_path import transmit_path
+from receive_path import receive_path
+
+try:
+    from gnuradio.qtgui import qtgui
+    from PyQt4 import QtGui, QtCore
+    import sip
+except ImportError:
+    print "Please install gr-qtgui."
+    sys.exit(1)
+    
+try:
+    from qt_digital_window2 import Ui_DigitalWindow
+except ImportError:
+    print "Error: could not find qt_digital_window2.py:"
+    print "\t\"pyuic4 qt_digital_window2.ui -o qt_digital_window2.py\""
+    sys.exit(1)
+
+
+#print os.getpid()
+#raw_input()
+
+
+# ////////////////////////////////////////////////////////////////////
+#        Define the QT Interface and Control Dialog
+# ////////////////////////////////////////////////////////////////////
+
+
+class dialog_box(QtGui.QMainWindow):
+    def __init__(self, snkTx, snkRx, fg, parent=None):
+
+        QtGui.QWidget.__init__(self, parent)
+        self.gui = Ui_DigitalWindow()
+        self.gui.setupUi(self)
+
+        self.fg = fg
+
+        self.set_sample_rate(self.fg.sample_rate())
+
+        self.set_snr(self.fg.snr())
+        self.set_frequency(self.fg.frequency_offset())
+        self.set_time_offset(self.fg.timing_offset())
+
+        self.set_alpha_time(self.fg.rx_timing_gain_alpha())
+        self.set_beta_time(self.fg.rx_timing_gain_beta())
+        self.set_alpha_freq(self.fg.rx_freq_gain_alpha())
+
+        # Add the qtsnk widgets to the hlayout box
+        self.gui.sinkLayout.addWidget(snkTx)
+        self.gui.sinkLayout.addWidget(snkRx)
+
+
+        # Connect up some signals
+        self.connect(self.gui.pauseButton, QtCore.SIGNAL("clicked()"),
+                     self.pauseFg)
+
+        self.connect(self.gui.sampleRateEdit, QtCore.SIGNAL("editingFinished()"),
+                     self.sampleRateEditText)
+
+        self.connect(self.gui.snrEdit, QtCore.SIGNAL("editingFinished()"),
+                     self.snrEditText)
+        self.connect(self.gui.freqEdit, QtCore.SIGNAL("editingFinished()"),
+                     self.freqEditText)
+        self.connect(self.gui.timeEdit, QtCore.SIGNAL("editingFinished()"),
+                     self.timeEditText)
+
+        self.connect(self.gui.alphaTimeEdit, QtCore.SIGNAL("editingFinished()"),
+                     self.alphaTimeEditText)
+        self.connect(self.gui.betaTimeEdit, QtCore.SIGNAL("editingFinished()"),
+                     self.betaTimeEditText)
+        self.connect(self.gui.alphaFreqEdit, QtCore.SIGNAL("editingFinished()"),
+                     self.alphaFreqEditText)
+
+        # Build a timer to update the packet number and PER fields
+        self.update_delay = 250  # time between updating packet rate fields
+        self.pkt_timer = QtCore.QTimer(self)
+        self.connect(self.pkt_timer, QtCore.SIGNAL("timeout()"),
+                     self.updatePacketInfo)
+        self.pkt_timer.start(self.update_delay)
+
+    def pauseFg(self):
+        if(self.gui.pauseButton.text() == "Pause"):
+            self.fg.stop()
+            self.fg.wait()
+            self.gui.pauseButton.setText("Unpause")
+        else:
+            self.fg.start()
+            self.gui.pauseButton.setText("Pause")
+
+    # Accessor functions for Gui to manipulate system parameters
+    def set_sample_rate(self, sr):
+        ssr = eng_notation.num_to_str(sr)
+        self.gui.sampleRateEdit.setText(QtCore.QString("%1").arg(ssr))
+
+    def sampleRateEditText(self):
+        try:
+            rate = self.gui.sampleRateEdit.text().toAscii()
+            srate = eng_notation.str_to_num(rate)
+            #self.fg.set_sample_rate(srate)
+        except RuntimeError:
+            pass
+
+
+    # Accessor functions for Gui to manipulate channel model
+    def set_snr(self, snr):
+        self.gui.snrEdit.setText(QtCore.QString("%1").arg(snr))
+
+    def set_frequency(self, fo):
+        self.gui.freqEdit.setText(QtCore.QString("%1").arg(fo))
+
+    def set_time_offset(self, to):
+        self.gui.timeEdit.setText(QtCore.QString("%1").arg(to))
+
+    def snrEditText(self):
+        try:
+            snr = self.gui.snrEdit.text().toDouble()[0]
+            self.fg.set_snr(snr)
+        except RuntimeError:
+            pass
+
+    def freqEditText(self):
+        try:
+            freq = self.gui.freqEdit.text().toDouble()[0]
+            self.fg.set_frequency_offset(freq)
+        except RuntimeError:
+            pass
+
+    def timeEditText(self):
+        try:
+            to = self.gui.timeEdit.text().toDouble()[0]
+            self.fg.set_timing_offset(to)
+        except RuntimeError:
+            pass
+
+
+    # Accessor functions for Gui to manipulate receiver parameters
+    def set_alpha_time(self, alpha):
+        self.gui.alphaTimeEdit.setText(QtCore.QString("%1").arg(alpha))
+
+    def set_beta_time(self, beta):
+        self.gui.betaTimeEdit.setText(QtCore.QString("%1").arg(beta))
+
+    def set_alpha_freq(self, alpha):
+        self.gui.alphaFreqEdit.setText(QtCore.QString("%1").arg(alpha))
+
+    def alphaFreqEditText(self):
+        try:
+            alpha = self.gui.alphaFreqEdit.text().toDouble()[0]
+            self.fg.set_rx_freq_gain_alpha(alpha)
+        except RuntimeError:
+            pass
+
+    def alphaTimeEditText(self):
+        try:
+            alpha = self.gui.alphaTimeEdit.text().toDouble()[0]
+            self.fg.set_rx_timing_gain_alpha(alpha)
+        except RuntimeError:
+            pass
+
+    def betaTimeEditText(self):
+        try:
+            beta = self.gui.betaTimeEdit.text().toDouble()[0]
+            self.fg.set_rx_timing_gain_beta(beta)
+        except RuntimeError:
+            pass
+
+    # Accessor functions for packet error reporting
+    def updatePacketInfo(self):
+        # Pull these globals in from the main thread
+        global n_rcvd, n_right, pktno
+
+        if(pktno > 0):
+            per = float(n_rcvd - n_right)/float(pktno)
+        else:
+            per = 0
+        self.gui.pktsRcvdEdit.setText(QtCore.QString("%1").arg(n_rcvd))
+        self.gui.pktsCorrectEdit.setText(QtCore.QString("%1").arg(n_right))
+        self.gui.perEdit.setText(QtCore.QString("%1").arg(per))
+
+
+
+# ////////////////////////////////////////////////////////////////////
+#        Define the GNU Radio Top Block
+# ////////////////////////////////////////////////////////////////////
+
+
+
+class my_top_block(gr.top_block):
+    def __init__(self, mod_class, demod_class, rx_callback, options):
+        gr.top_block.__init__(self)
+
+        self._sample_rate = options.sample_rate
+
+        channelon = True;
+
+        self.gui_on = options.gui
+
+        self._frequency_offset = options.frequency_offset
+        self._timing_offset = options.timing_offset
+        self._tx_amplitude = options.tx_amplitude
+        self._snr_dB = options.snr
+
+        self._noise_voltage = self.get_noise_voltage(self._snr_dB)
+
+        self.txpath = transmit_path(mod_class, options)
+        self.throttle = gr.throttle(gr.sizeof_gr_complex, self.sample_rate())
+        self.rxpath = receive_path(demod_class, rx_callback, options)
+
+        # FIXME: do better exposure to lower issues for control
+        self._timing_gain_alpha = self.rxpath.packet_receiver._demodulator._timing_alpha
+        self._timing_gain_beta = self.rxpath.packet_receiver._demodulator._timing_beta
+        self._freq_gain_alpha = self.rxpath.packet_receiver._demodulator._costas_alpha
+
+        if channelon:
+            self.channel = gr.channel_model(self._noise_voltage,
+                                            self.frequency_offset(),
+                                            self.timing_offset())
+            
+            if options.discontinuous:
+                z = 20000*[0,]
+                self.zeros = gr.vector_source_c(z, True)
+                packet_size = 5*((4+8+4+1500+4) * 8)
+                self.mux = gr.stream_mux(gr.sizeof_gr_complex, [packet_size-0, int(9e5)])
+
+                # Connect components
+                self.connect(self.txpath, self.throttle, (self.mux,0))
+                self.connect(self.zeros, (self.mux,1))
+                self.connect(self.mux, self.channel, self.rxpath)
+
+            else:
+                self.connect(self.txpath, self.throttle, self.channel, self.rxpath)
+
+            if self.gui_on:
+                self.qapp = QtGui.QApplication(sys.argv)
+                fftsize = 2048
+
+                self.snk_tx = qtgui.sink_c(fftsize, gr.firdes.WIN_BLACKMAN_hARRIS,
+                                           0, 1,
+                                           "Tx", True, True, False, True, True)
+                self.snk_rx = qtgui.sink_c(fftsize, gr.firdes.WIN_BLACKMAN_hARRIS,
+                                           0, 1,
+                                           "Rx", True, True, False, True, True)
+
+                self.snk_tx.set_frequency_axis(-80, 0)
+                self.snk_rx.set_frequency_axis(-60, 20)
+            
+                # Connect to the QT sinks
+                # FIXME: make better exposure to receiver from rxpath
+                self.freq_recov = self.rxpath.packet_receiver._demodulator.clock_recov
+                self.time_recov = self.rxpath.packet_receiver._demodulator.time_recov
+                self.freq_recov.set_alpha(self._freq_gain_alpha)
+                self.freq_recov.set_beta(0.25*self._freq_gain_alpha*self._freq_gain_alpha)
+                self.time_recov.set_alpha(self._timing_gain_alpha)
+                self.time_recov.set_beta(self._timing_gain_beta)
+                self.connect(self.channel, self.snk_tx)
+                self.connect(self.time_recov, self.snk_rx)
+
+                pyTxQt  = self.snk_tx.pyqwidget()
+                pyTx = sip.wrapinstance(pyTxQt, QtGui.QWidget)
+                 
+                pyRxQt  = self.snk_rx.pyqwidget()
+                pyRx = sip.wrapinstance(pyRxQt, QtGui.QWidget)
+
+                self.main_box = dialog_box(pyTx, pyRx, self)
+                self.main_box.show()
+                
+        else:
+            # Connect components
+            self.connect(self.txpath, self.throttle, self.rxpath)
+
+
+
+    # System Parameters
+    def sample_rate(self):
+        return self._sample_rate
+    
+    def set_sample_rate(self, sr):
+        self._sample_rate = sr
+        #self.throttle.set_samples_per_second(self._sample_rate)
+
+    # Channel Model Parameters
+    def snr(self):
+        return self._snr_dB
+    
+    def set_snr(self, snr):
+        self._snr_dB = snr
+        self._noise_voltage = self.get_noise_voltage(self._snr_dB)
+        self.channel.set_noise_voltage(self._noise_voltage)
+
+    def get_noise_voltage(self, SNR):
+        snr = 10.0**(SNR/10.0)        
+        power_in_signal = abs(self._tx_amplitude)**2
+        noise_power = power_in_signal/snr
+        noise_voltage = math.sqrt(noise_power)
+        return noise_voltage
+
+    def frequency_offset(self):
+        return self._frequency_offset * self.sample_rate()
+
+    def set_frequency_offset(self, fo):
+        self._frequency_offset = fo / self.sample_rate()
+        self.channel.set_frequency_offset(self._frequency_offset)
+
+    def timing_offset(self):
+        return self._timing_offset
+    
+    def set_timing_offset(self, to):
+        self._timing_offset = to
+        self.channel.set_timing_offset(self._timing_offset)
+
+
+    # Receiver Parameters
+    def rx_timing_gain_alpha(self):
+        return self._timing_gain_alpha
+
+    def rx_timing_gain_beta(self):
+        return self._timing_gain_beta
+    
+    def set_rx_timing_gain_alpha(self, gain):
+        self._timing_gain_alpha = gain
+        self.time_recov.set_alpha(self._timing_gain_alpha)
+
+    def set_rx_timing_gain_beta(self, gain):
+        self._timing_gain_beta = gain
+        self.time_recov.set_beta(self._timing_gain_beta)
+
+    def rx_freq_gain_alpha(self):
+        return self._freq_gain_alpha
+
+    def rx_freq_gain_beta(self):
+        return self._freq_gain_beta
+    
+    def set_rx_freq_gain_alpha(self, alpha):
+        self._freq_gain_alpha = alpha
+        self._freq_gain_beta = .25 * self._freq_gain_alpha * self._freq_gain_alpha
+        self.freq_recov.set_alpha(self._freq_gain_alpha)
+        self.freq_recov.set_beta(self._freq_gain_beta)
+
+
+
+# /////////////////////////////////////////////////////////////////////////////
+#       Thread to handle the packet sending procedure
+#          Operates in parallel with qApp.exec_()       
+# /////////////////////////////////////////////////////////////////////////////
+
+
+
+class th_send(Thread):
+    def __init__(self, send_fnc, megs, sz):
+        Thread.__init__(self)
+        self.send = send_fnc
+        self.nbytes = int(1e6 * megs)
+        self.pkt_size = int(sz)
+
+    def run(self):
+        # generate and send packets
+        n = 0
+        pktno = 0
+        
+        while n < self.nbytes:
+            self.send(struct.pack('!H', pktno & 0xffff) +
+                      (self.pkt_size - 2) * chr(pktno & 0xff))
+            n += self.pkt_size
+            pktno += 1
+            
+        self.send(eof=True)
+
+    def stop(self):
+        self.nbytes = 0
+
+
+
+# /////////////////////////////////////////////////////////////////////////////
+#                                   main
+# /////////////////////////////////////////////////////////////////////////////
+
+
+
+def main():
+
+    global n_rcvd, n_right, pktno
+
+    n_rcvd = 0
+    n_right = 0
+    pktno = 0
+    
+    def rx_callback(ok, payload):
+        global n_rcvd, n_right, pktno
+        (pktno,) = struct.unpack('!H', payload[0:2])
+        n_rcvd += 1
+        if ok:
+            n_right += 1
+
+        if not options.gui:
+            print "ok = %5s  pktno = %4d  n_rcvd = %4d  n_right = %4d" % (
+                ok, pktno, n_rcvd, n_right)
+        
+
+    def send_pkt(payload='', eof=False):
+        return tb.txpath.send_pkt(payload, eof)
+
+    mods = modulation_utils.type_1_mods()
+    demods = modulation_utils.type_1_demods()
+
+    parser = OptionParser(option_class=eng_option, conflict_handler="resolve")
+    expert_grp = parser.add_option_group("Expert")
+    channel_grp = parser.add_option_group("Channel")
+
+    parser.add_option("-m", "--modulation", type="choice", choices=mods.keys(),
+                      default='dbpsk',
+                      help="Select modulation from: %s [default=%%default]"
+                            % (', '.join(mods.keys()),))
+
+    parser.add_option("-s", "--size", type="eng_float", default=1500,
+                      help="set packet size [default=%default]")
+    parser.add_option("-M", "--megabytes", type="eng_float", default=1.0,
+                      help="set megabytes to transmit [default=%default]")
+    parser.add_option("","--discontinuous", action="store_true", default=False,
+                      help="enable discontinous transmission (bursts of 5 packets)")
+    parser.add_option("-G", "--gui", action="store_true", default=False,
+                      help="Turn on the GUI [default=%default]")
+
+    channel_grp.add_option("", "--sample-rate", type="eng_float", default=1e5,
+                           help="set speed of channel/simulation rate to RATE [default=%default]") 
+    channel_grp.add_option("", "--snr", type="eng_float", default=30,
+                           help="set the SNR of the channel in dB [default=%default]")
+    channel_grp.add_option("", "--frequency-offset", type="eng_float", default=0,
+                           help="set frequency offset introduced by channel [default=%default]")
+    channel_grp.add_option("", "--timing-offset", type="eng_float", default=1.0,
+                           help="set timing offset introduced by channel [default=%default]")
+    channel_grp.add_option("", "--seed", action="store_true", default=False,
+                           help="use a random seed for AWGN noise [default=%default]")
+
+    transmit_path.add_options(parser, expert_grp)
+    receive_path.add_options(parser, expert_grp)
+
+    for mod in mods.values():
+        mod.add_options(expert_grp)
+    for demod in demods.values():
+        demod.add_options(expert_grp)
+
+    (options, args) = parser.parse_args ()
+
+    if len(args) != 0:
+        parser.print_help()
+        sys.exit(1)
+        
+    r = gr.enable_realtime_scheduling()
+    if r != gr.RT_OK:
+        print "Warning: failed to enable realtime scheduling"
+        
+    # Create an instance of a hierarchical block
+    tb = my_top_block(mods[options.modulation],
+                      demods[options.modulation],
+                      rx_callback, options)
+    tb.start()
+
+    packet_sender = th_send(send_pkt, options.megabytes, options.size)
+    packet_sender.start()
+
+    if(options.gui):
+        tb.qapp.exec_()
+        packet_sender.stop()
+    else:
+        # Process until done; hack in to the join to stop on an interrupt
+        while(packet_sender.isAlive()):
+            try:
+                packet_sender.join(1)
+            except KeyboardInterrupt:
+                packet_sender.stop()
+        
+    
+if __name__ == '__main__':
+    try:
+        main()
+    except KeyboardInterrupt:
+        pass
diff --git a/gnuradio-examples/python/digital/qt_digital_window.py b/gnuradio-examples/python/digital/qt_digital_window.py
index e3feb57c9..6e0f25212 100644
--- a/gnuradio-examples/python/digital/qt_digital_window.py
+++ b/gnuradio-examples/python/digital/qt_digital_window.py
@@ -2,8 +2,8 @@
 
 # Form implementation generated from reading ui file 'qt_digital_window.ui'
 #
-# Created: Fri Jul  3 10:03:54 2009
-#      by: PyQt4 UI code generator 4.4.3
+# Created: Tue Oct  6 11:27:37 2009
+#      by: PyQt4 UI code generator 4.4.4
 #
 # WARNING! All changes made in this file will be lost!
 
@@ -12,53 +12,63 @@ from PyQt4 import QtCore, QtGui
 class Ui_DigitalWindow(object):
     def setupUi(self, DigitalWindow):
         DigitalWindow.setObjectName("DigitalWindow")
-        DigitalWindow.resize(1050, 752)
+        DigitalWindow.resize(1019, 754)
         self.centralwidget = QtGui.QWidget(DigitalWindow)
         self.centralwidget.setObjectName("centralwidget")
         self.gridLayout = QtGui.QGridLayout(self.centralwidget)
         self.gridLayout.setObjectName("gridLayout")
-        self.verticalLayout_2 = QtGui.QVBoxLayout()
-        self.verticalLayout_2.setObjectName("verticalLayout_2")
-        self.sysBox = QtGui.QGroupBox(self.centralwidget)
-        sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
-        sizePolicy.setHorizontalStretch(0)
-        sizePolicy.setVerticalStretch(0)
-        sizePolicy.setHeightForWidth(self.sysBox.sizePolicy().hasHeightForWidth())
-        self.sysBox.setSizePolicy(sizePolicy)
-        self.sysBox.setMinimumSize(QtCore.QSize(240, 60))
-        self.sysBox.setMaximumSize(QtCore.QSize(240, 16777215))
-        self.sysBox.setObjectName("sysBox")
-        self.formLayoutWidget = QtGui.QWidget(self.sysBox)
-        self.formLayoutWidget.setGeometry(QtCore.QRect(10, 20, 221, 31))
-        self.formLayoutWidget.setObjectName("formLayoutWidget")
-        self.formLayout = QtGui.QFormLayout(self.formLayoutWidget)
-        self.formLayout.setSizeConstraint(QtGui.QLayout.SetFixedSize)
-        self.formLayout.setVerticalSpacing(20)
-        self.formLayout.setObjectName("formLayout")
-        self.sampleRateEdit = QtGui.QLineEdit(self.formLayoutWidget)
-        sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
-        sizePolicy.setHorizontalStretch(0)
-        sizePolicy.setVerticalStretch(0)
-        sizePolicy.setHeightForWidth(self.sampleRateEdit.sizePolicy().hasHeightForWidth())
-        self.sampleRateEdit.setSizePolicy(sizePolicy)
-        self.sampleRateEdit.setMinimumSize(QtCore.QSize(100, 26))
-        self.sampleRateEdit.setMaximumSize(QtCore.QSize(100, 26))
-        self.sampleRateEdit.setObjectName("sampleRateEdit")
-        self.formLayout.setWidget(0, QtGui.QFormLayout.FieldRole, self.sampleRateEdit)
-        self.sampleRateLabel = QtGui.QLabel(self.formLayoutWidget)
+        self.verticalLayout_3 = QtGui.QVBoxLayout()
+        self.verticalLayout_3.setObjectName("verticalLayout_3")
+        self.rxBox = QtGui.QGroupBox(self.centralwidget)
         sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
         sizePolicy.setHorizontalStretch(0)
         sizePolicy.setVerticalStretch(0)
-        sizePolicy.setHeightForWidth(self.sampleRateLabel.sizePolicy().hasHeightForWidth())
-        self.sampleRateLabel.setSizePolicy(sizePolicy)
-        self.sampleRateLabel.setMinimumSize(QtCore.QSize(0, 20))
-        self.sampleRateLabel.setMaximumSize(QtCore.QSize(16777215, 20))
-        self.sampleRateLabel.setObjectName("sampleRateLabel")
-        self.formLayout.setWidget(0, QtGui.QFormLayout.LabelRole, self.sampleRateLabel)
-        self.verticalLayout_2.addWidget(self.sysBox)
-        spacerItem = QtGui.QSpacerItem(20, 60, QtGui.QSizePolicy.Minimum, QtGui.QSizePolicy.Fixed)
-        self.verticalLayout_2.addItem(spacerItem)
-        self.gridLayout.addLayout(self.verticalLayout_2, 2, 0, 1, 1)
+        sizePolicy.setHeightForWidth(self.rxBox.sizePolicy().hasHeightForWidth())
+        self.rxBox.setSizePolicy(sizePolicy)
+        self.rxBox.setMinimumSize(QtCore.QSize(180, 90))
+        self.rxBox.setMaximumSize(QtCore.QSize(180, 16777215))
+        self.rxBox.setObjectName("rxBox")
+        self.formLayoutWidget_3 = QtGui.QWidget(self.rxBox)
+        self.formLayoutWidget_3.setGeometry(QtCore.QRect(10, 20, 141, 61))
+        self.formLayoutWidget_3.setObjectName("formLayoutWidget_3")
+        self.formLayout_3 = QtGui.QFormLayout(self.formLayoutWidget_3)
+        self.formLayout_3.setSizeConstraint(QtGui.QLayout.SetFixedSize)
+        self.formLayout_3.setObjectName("formLayout_3")
+        self.gainMuLabel = QtGui.QLabel(self.formLayoutWidget_3)
+        self.gainMuLabel.setObjectName("gainMuLabel")
+        self.formLayout_3.setWidget(0, QtGui.QFormLayout.LabelRole, self.gainMuLabel)
+        self.alphaLabel = QtGui.QLabel(self.formLayoutWidget_3)
+        self.alphaLabel.setObjectName("alphaLabel")
+        self.formLayout_3.setWidget(1, QtGui.QFormLayout.LabelRole, self.alphaLabel)
+        self.gainMuEdit = QtGui.QLineEdit(self.formLayoutWidget_3)
+        self.gainMuEdit.setMinimumSize(QtCore.QSize(60, 0))
+        self.gainMuEdit.setMaximumSize(QtCore.QSize(80, 16777215))
+        self.gainMuEdit.setObjectName("gainMuEdit")
+        self.formLayout_3.setWidget(0, QtGui.QFormLayout.FieldRole, self.gainMuEdit)
+        self.alphaEdit = QtGui.QLineEdit(self.formLayoutWidget_3)
+        self.alphaEdit.setMinimumSize(QtCore.QSize(60, 0))
+        self.alphaEdit.setMaximumSize(QtCore.QSize(80, 16777215))
+        self.alphaEdit.setObjectName("alphaEdit")
+        self.formLayout_3.setWidget(1, QtGui.QFormLayout.FieldRole, self.alphaEdit)
+        self.verticalLayout_3.addWidget(self.rxBox)
+        spacerItem = QtGui.QSpacerItem(20, 30, QtGui.QSizePolicy.Minimum, QtGui.QSizePolicy.Fixed)
+        self.verticalLayout_3.addItem(spacerItem)
+        self.gridLayout.addLayout(self.verticalLayout_3, 2, 2, 1, 1)
+        self.verticalLayout = QtGui.QVBoxLayout()
+        self.verticalLayout.setObjectName("verticalLayout")
+        self.pauseButton = QtGui.QPushButton(self.centralwidget)
+        self.pauseButton.setMinimumSize(QtCore.QSize(80, 0))
+        self.pauseButton.setMaximumSize(QtCore.QSize(80, 16777215))
+        self.pauseButton.setObjectName("pauseButton")
+        self.verticalLayout.addWidget(self.pauseButton)
+        spacerItem1 = QtGui.QSpacerItem(20, 60, QtGui.QSizePolicy.Minimum, QtGui.QSizePolicy.Fixed)
+        self.verticalLayout.addItem(spacerItem1)
+        self.closeButton = QtGui.QPushButton(self.centralwidget)
+        self.closeButton.setMinimumSize(QtCore.QSize(80, 0))
+        self.closeButton.setMaximumSize(QtCore.QSize(80, 16777215))
+        self.closeButton.setObjectName("closeButton")
+        self.verticalLayout.addWidget(self.closeButton)
+        self.gridLayout.addLayout(self.verticalLayout, 2, 5, 1, 1)
         self.channelModeBox = QtGui.QGroupBox(self.centralwidget)
         sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
         sizePolicy.setHorizontalStretch(0)
@@ -69,7 +79,7 @@ class Ui_DigitalWindow(object):
         self.channelModeBox.setMaximumSize(QtCore.QSize(245, 16777215))
         self.channelModeBox.setObjectName("channelModeBox")
         self.formLayoutWidget_2 = QtGui.QWidget(self.channelModeBox)
-        self.formLayoutWidget_2.setGeometry(QtCore.QRect(10, 20, 231, 98))
+        self.formLayoutWidget_2.setGeometry(QtCore.QRect(10, 20, 221, 98))
         self.formLayoutWidget_2.setObjectName("formLayoutWidget_2")
         self.formLayout_2 = QtGui.QFormLayout(self.formLayoutWidget_2)
         self.formLayout_2.setSizeConstraint(QtGui.QLayout.SetFixedSize)
@@ -79,83 +89,69 @@ class Ui_DigitalWindow(object):
         self.snrLabel.setObjectName("snrLabel")
         self.formLayout_2.setWidget(0, QtGui.QFormLayout.LabelRole, self.snrLabel)
         self.snrEdit = QtGui.QLineEdit(self.formLayoutWidget_2)
-        self.snrEdit.setMinimumSize(QtCore.QSize(100, 0))
-        self.snrEdit.setMaximumSize(QtCore.QSize(100, 16777215))
+        self.snrEdit.setMinimumSize(QtCore.QSize(60, 0))
+        self.snrEdit.setMaximumSize(QtCore.QSize(80, 16777215))
         self.snrEdit.setObjectName("snrEdit")
         self.formLayout_2.setWidget(0, QtGui.QFormLayout.FieldRole, self.snrEdit)
         self.freqLabel = QtGui.QLabel(self.formLayoutWidget_2)
         self.freqLabel.setObjectName("freqLabel")
         self.formLayout_2.setWidget(1, QtGui.QFormLayout.LabelRole, self.freqLabel)
         self.freqEdit = QtGui.QLineEdit(self.formLayoutWidget_2)
-        self.freqEdit.setMinimumSize(QtCore.QSize(100, 0))
-        self.freqEdit.setMaximumSize(QtCore.QSize(100, 16777215))
+        self.freqEdit.setMinimumSize(QtCore.QSize(60, 0))
+        self.freqEdit.setMaximumSize(QtCore.QSize(80, 16777215))
         self.freqEdit.setObjectName("freqEdit")
         self.formLayout_2.setWidget(1, QtGui.QFormLayout.FieldRole, self.freqEdit)
         self.timeLabel = QtGui.QLabel(self.formLayoutWidget_2)
         self.timeLabel.setObjectName("timeLabel")
         self.formLayout_2.setWidget(2, QtGui.QFormLayout.LabelRole, self.timeLabel)
         self.timeEdit = QtGui.QLineEdit(self.formLayoutWidget_2)
-        self.timeEdit.setMinimumSize(QtCore.QSize(100, 0))
-        self.timeEdit.setMaximumSize(QtCore.QSize(100, 16777215))
+        self.timeEdit.setMinimumSize(QtCore.QSize(60, 0))
+        self.timeEdit.setMaximumSize(QtCore.QSize(80, 16777215))
         self.timeEdit.setObjectName("timeEdit")
         self.formLayout_2.setWidget(2, QtGui.QFormLayout.FieldRole, self.timeEdit)
         self.gridLayout.addWidget(self.channelModeBox, 2, 1, 1, 1)
-        self.verticalLayout_5 = QtGui.QVBoxLayout()
-        self.verticalLayout_5.setObjectName("verticalLayout_5")
-        self.sinkFrame = QtGui.QFrame(self.centralwidget)
-        sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Expanding, QtGui.QSizePolicy.Expanding)
+        self.verticalLayout_2 = QtGui.QVBoxLayout()
+        self.verticalLayout_2.setObjectName("verticalLayout_2")
+        self.sysBox = QtGui.QGroupBox(self.centralwidget)
+        sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
         sizePolicy.setHorizontalStretch(0)
         sizePolicy.setVerticalStretch(0)
-        sizePolicy.setHeightForWidth(self.sinkFrame.sizePolicy().hasHeightForWidth())
-        self.sinkFrame.setSizePolicy(sizePolicy)
-        self.sinkFrame.setMinimumSize(QtCore.QSize(1000, 550))
-        self.sinkFrame.setFrameShape(QtGui.QFrame.StyledPanel)
-        self.sinkFrame.setFrameShadow(QtGui.QFrame.Raised)
-        self.sinkFrame.setObjectName("sinkFrame")
-        self.gridLayout_2 = QtGui.QGridLayout(self.sinkFrame)
-        self.gridLayout_2.setObjectName("gridLayout_2")
-        self.sinkLayout = QtGui.QHBoxLayout()
-        self.sinkLayout.setObjectName("sinkLayout")
-        self.gridLayout_2.addLayout(self.sinkLayout, 1, 0, 1, 1)
-        self.verticalLayout_5.addWidget(self.sinkFrame)
-        self.gridLayout.addLayout(self.verticalLayout_5, 0, 0, 1, 6)
-        self.verticalLayout_3 = QtGui.QVBoxLayout()
-        self.verticalLayout_3.setObjectName("verticalLayout_3")
-        self.rxBox = QtGui.QGroupBox(self.centralwidget)
+        sizePolicy.setHeightForWidth(self.sysBox.sizePolicy().hasHeightForWidth())
+        self.sysBox.setSizePolicy(sizePolicy)
+        self.sysBox.setMinimumSize(QtCore.QSize(240, 60))
+        self.sysBox.setMaximumSize(QtCore.QSize(240, 16777215))
+        self.sysBox.setObjectName("sysBox")
+        self.formLayoutWidget = QtGui.QWidget(self.sysBox)
+        self.formLayoutWidget.setGeometry(QtCore.QRect(10, 20, 211, 31))
+        self.formLayoutWidget.setObjectName("formLayoutWidget")
+        self.formLayout = QtGui.QFormLayout(self.formLayoutWidget)
+        self.formLayout.setSizeConstraint(QtGui.QLayout.SetFixedSize)
+        self.formLayout.setVerticalSpacing(20)
+        self.formLayout.setObjectName("formLayout")
+        self.sampleRateEdit = QtGui.QLineEdit(self.formLayoutWidget)
         sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
         sizePolicy.setHorizontalStretch(0)
         sizePolicy.setVerticalStretch(0)
-        sizePolicy.setHeightForWidth(self.rxBox.sizePolicy().hasHeightForWidth())
-        self.rxBox.setSizePolicy(sizePolicy)
-        self.rxBox.setMinimumSize(QtCore.QSize(180, 90))
-        self.rxBox.setMaximumSize(QtCore.QSize(180, 16777215))
-        self.rxBox.setObjectName("rxBox")
-        self.formLayoutWidget_3 = QtGui.QWidget(self.rxBox)
-        self.formLayoutWidget_3.setGeometry(QtCore.QRect(10, 20, 161, 61))
-        self.formLayoutWidget_3.setObjectName("formLayoutWidget_3")
-        self.formLayout_3 = QtGui.QFormLayout(self.formLayoutWidget_3)
-        self.formLayout_3.setSizeConstraint(QtGui.QLayout.SetFixedSize)
-        self.formLayout_3.setObjectName("formLayout_3")
-        self.gainMuLabel = QtGui.QLabel(self.formLayoutWidget_3)
-        self.gainMuLabel.setObjectName("gainMuLabel")
-        self.formLayout_3.setWidget(0, QtGui.QFormLayout.LabelRole, self.gainMuLabel)
-        self.alphaLabel = QtGui.QLabel(self.formLayoutWidget_3)
-        self.alphaLabel.setObjectName("alphaLabel")
-        self.formLayout_3.setWidget(1, QtGui.QFormLayout.LabelRole, self.alphaLabel)
-        self.gainMuEdit = QtGui.QLineEdit(self.formLayoutWidget_3)
-        self.gainMuEdit.setMinimumSize(QtCore.QSize(100, 0))
-        self.gainMuEdit.setMaximumSize(QtCore.QSize(100, 16777215))
-        self.gainMuEdit.setObjectName("gainMuEdit")
-        self.formLayout_3.setWidget(0, QtGui.QFormLayout.FieldRole, self.gainMuEdit)
-        self.alphaEdit = QtGui.QLineEdit(self.formLayoutWidget_3)
-        self.alphaEdit.setMinimumSize(QtCore.QSize(100, 0))
-        self.alphaEdit.setMaximumSize(QtCore.QSize(100, 16777215))
-        self.alphaEdit.setObjectName("alphaEdit")
-        self.formLayout_3.setWidget(1, QtGui.QFormLayout.FieldRole, self.alphaEdit)
-        self.verticalLayout_3.addWidget(self.rxBox)
-        spacerItem1 = QtGui.QSpacerItem(20, 30, QtGui.QSizePolicy.Minimum, QtGui.QSizePolicy.Fixed)
-        self.verticalLayout_3.addItem(spacerItem1)
-        self.gridLayout.addLayout(self.verticalLayout_3, 2, 2, 1, 1)
+        sizePolicy.setHeightForWidth(self.sampleRateEdit.sizePolicy().hasHeightForWidth())
+        self.sampleRateEdit.setSizePolicy(sizePolicy)
+        self.sampleRateEdit.setMinimumSize(QtCore.QSize(60, 26))
+        self.sampleRateEdit.setMaximumSize(QtCore.QSize(80, 26))
+        self.sampleRateEdit.setObjectName("sampleRateEdit")
+        self.formLayout.setWidget(0, QtGui.QFormLayout.FieldRole, self.sampleRateEdit)
+        self.sampleRateLabel = QtGui.QLabel(self.formLayoutWidget)
+        sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(self.sampleRateLabel.sizePolicy().hasHeightForWidth())
+        self.sampleRateLabel.setSizePolicy(sizePolicy)
+        self.sampleRateLabel.setMinimumSize(QtCore.QSize(0, 20))
+        self.sampleRateLabel.setMaximumSize(QtCore.QSize(16777215, 20))
+        self.sampleRateLabel.setObjectName("sampleRateLabel")
+        self.formLayout.setWidget(0, QtGui.QFormLayout.LabelRole, self.sampleRateLabel)
+        self.verticalLayout_2.addWidget(self.sysBox)
+        spacerItem2 = QtGui.QSpacerItem(20, 60, QtGui.QSizePolicy.Minimum, QtGui.QSizePolicy.Fixed)
+        self.verticalLayout_2.addItem(spacerItem2)
+        self.gridLayout.addLayout(self.verticalLayout_2, 2, 0, 1, 1)
         self.rxBox_2 = QtGui.QGroupBox(self.centralwidget)
         sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
         sizePolicy.setHorizontalStretch(0)
@@ -166,7 +162,7 @@ class Ui_DigitalWindow(object):
         self.rxBox_2.setMaximumSize(QtCore.QSize(265, 125))
         self.rxBox_2.setObjectName("rxBox_2")
         self.formLayoutWidget_4 = QtGui.QWidget(self.rxBox_2)
-        self.formLayoutWidget_4.setGeometry(QtCore.QRect(10, 20, 201, 92))
+        self.formLayoutWidget_4.setGeometry(QtCore.QRect(10, 20, 181, 92))
         self.formLayoutWidget_4.setObjectName("formLayoutWidget_4")
         self.formLayout_4 = QtGui.QFormLayout(self.formLayoutWidget_4)
         self.formLayout_4.setSizeConstraint(QtGui.QLayout.SetFixedSize)
@@ -181,41 +177,45 @@ class Ui_DigitalWindow(object):
         self.perLabel.setObjectName("perLabel")
         self.formLayout_4.setWidget(2, QtGui.QFormLayout.LabelRole, self.perLabel)
         self.pktsRcvdEdit = QtGui.QLineEdit(self.formLayoutWidget_4)
-        self.pktsRcvdEdit.setMinimumSize(QtCore.QSize(100, 0))
-        self.pktsRcvdEdit.setMaximumSize(QtCore.QSize(100, 16777215))
+        self.pktsRcvdEdit.setMinimumSize(QtCore.QSize(60, 0))
+        self.pktsRcvdEdit.setMaximumSize(QtCore.QSize(80, 16777215))
         self.pktsRcvdEdit.setObjectName("pktsRcvdEdit")
         self.formLayout_4.setWidget(0, QtGui.QFormLayout.FieldRole, self.pktsRcvdEdit)
         self.pktsCorrectEdit = QtGui.QLineEdit(self.formLayoutWidget_4)
-        self.pktsCorrectEdit.setMinimumSize(QtCore.QSize(100, 0))
-        self.pktsCorrectEdit.setMaximumSize(QtCore.QSize(100, 16777215))
+        self.pktsCorrectEdit.setMinimumSize(QtCore.QSize(60, 0))
+        self.pktsCorrectEdit.setMaximumSize(QtCore.QSize(80, 16777215))
         self.pktsCorrectEdit.setObjectName("pktsCorrectEdit")
         self.formLayout_4.setWidget(1, QtGui.QFormLayout.FieldRole, self.pktsCorrectEdit)
         self.perEdit = QtGui.QLineEdit(self.formLayoutWidget_4)
-        self.perEdit.setMinimumSize(QtCore.QSize(100, 0))
-        self.perEdit.setMaximumSize(QtCore.QSize(100, 16777215))
+        self.perEdit.setMinimumSize(QtCore.QSize(60, 0))
+        self.perEdit.setMaximumSize(QtCore.QSize(80, 16777215))
         self.perEdit.setObjectName("perEdit")
         self.formLayout_4.setWidget(2, QtGui.QFormLayout.FieldRole, self.perEdit)
         self.gridLayout.addWidget(self.rxBox_2, 2, 3, 1, 1)
-        spacerItem2 = QtGui.QSpacerItem(20, 20, QtGui.QSizePolicy.Expanding, QtGui.QSizePolicy.Minimum)
-        self.gridLayout.addItem(spacerItem2, 2, 4, 1, 1)
-        self.verticalLayout = QtGui.QVBoxLayout()
-        self.verticalLayout.setObjectName("verticalLayout")
-        self.pauseButton = QtGui.QPushButton(self.centralwidget)
-        self.pauseButton.setMinimumSize(QtCore.QSize(80, 0))
-        self.pauseButton.setMaximumSize(QtCore.QSize(80, 16777215))
-        self.pauseButton.setObjectName("pauseButton")
-        self.verticalLayout.addWidget(self.pauseButton)
-        spacerItem3 = QtGui.QSpacerItem(20, 60, QtGui.QSizePolicy.Minimum, QtGui.QSizePolicy.Fixed)
-        self.verticalLayout.addItem(spacerItem3)
-        self.closeButton = QtGui.QPushButton(self.centralwidget)
-        self.closeButton.setMinimumSize(QtCore.QSize(80, 0))
-        self.closeButton.setMaximumSize(QtCore.QSize(80, 16777215))
-        self.closeButton.setObjectName("closeButton")
-        self.verticalLayout.addWidget(self.closeButton)
-        self.gridLayout.addLayout(self.verticalLayout, 2, 5, 1, 1)
+        spacerItem3 = QtGui.QSpacerItem(20, 20, QtGui.QSizePolicy.Expanding, QtGui.QSizePolicy.Minimum)
+        self.gridLayout.addItem(spacerItem3, 2, 4, 1, 1)
+        self.verticalLayout_5 = QtGui.QVBoxLayout()
+        self.verticalLayout_5.setObjectName("verticalLayout_5")
+        self.sinkFrame = QtGui.QFrame(self.centralwidget)
+        sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Expanding, QtGui.QSizePolicy.Expanding)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(self.sinkFrame.sizePolicy().hasHeightForWidth())
+        self.sinkFrame.setSizePolicy(sizePolicy)
+        self.sinkFrame.setMinimumSize(QtCore.QSize(500, 550))
+        self.sinkFrame.setFrameShape(QtGui.QFrame.StyledPanel)
+        self.sinkFrame.setFrameShadow(QtGui.QFrame.Raised)
+        self.sinkFrame.setObjectName("sinkFrame")
+        self.gridLayout_2 = QtGui.QGridLayout(self.sinkFrame)
+        self.gridLayout_2.setObjectName("gridLayout_2")
+        self.sinkLayout = QtGui.QHBoxLayout()
+        self.sinkLayout.setObjectName("sinkLayout")
+        self.gridLayout_2.addLayout(self.sinkLayout, 1, 0, 1, 1)
+        self.verticalLayout_5.addWidget(self.sinkFrame)
+        self.gridLayout.addLayout(self.verticalLayout_5, 0, 0, 1, 6)
         DigitalWindow.setCentralWidget(self.centralwidget)
         self.menubar = QtGui.QMenuBar(DigitalWindow)
-        self.menubar.setGeometry(QtCore.QRect(0, 0, 1050, 24))
+        self.menubar.setGeometry(QtCore.QRect(0, 0, 1019, 25))
         self.menubar.setObjectName("menubar")
         self.menuFile = QtGui.QMenu(self.menubar)
         self.menuFile.setObjectName("menuFile")
@@ -237,21 +237,21 @@ class Ui_DigitalWindow(object):
 
     def retranslateUi(self, DigitalWindow):
         DigitalWindow.setWindowTitle(QtGui.QApplication.translate("DigitalWindow", "MainWindow", None, QtGui.QApplication.UnicodeUTF8))
-        self.sysBox.setTitle(QtGui.QApplication.translate("DigitalWindow", "System Parameters", None, QtGui.QApplication.UnicodeUTF8))
-        self.sampleRateLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Sample Rate (sps)", None, QtGui.QApplication.UnicodeUTF8))
+        self.rxBox.setTitle(QtGui.QApplication.translate("DigitalWindow", "Receiver Parameters", None, QtGui.QApplication.UnicodeUTF8))
+        self.gainMuLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Gain mu", None, QtGui.QApplication.UnicodeUTF8))
+        self.alphaLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Alpha", None, QtGui.QApplication.UnicodeUTF8))
+        self.pauseButton.setText(QtGui.QApplication.translate("DigitalWindow", "Pause", None, QtGui.QApplication.UnicodeUTF8))
+        self.closeButton.setText(QtGui.QApplication.translate("DigitalWindow", "Close", None, QtGui.QApplication.UnicodeUTF8))
         self.channelModeBox.setTitle(QtGui.QApplication.translate("DigitalWindow", "Channel Model Parameters", None, QtGui.QApplication.UnicodeUTF8))
         self.snrLabel.setText(QtGui.QApplication.translate("DigitalWindow", "SNR (dB)", None, QtGui.QApplication.UnicodeUTF8))
         self.freqLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Frequency Offset (Hz)", None, QtGui.QApplication.UnicodeUTF8))
         self.timeLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Timing Offset", None, QtGui.QApplication.UnicodeUTF8))
-        self.rxBox.setTitle(QtGui.QApplication.translate("DigitalWindow", "Receiver Parameters", None, QtGui.QApplication.UnicodeUTF8))
-        self.gainMuLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Gain mu", None, QtGui.QApplication.UnicodeUTF8))
-        self.alphaLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Alpha", None, QtGui.QApplication.UnicodeUTF8))
+        self.sysBox.setTitle(QtGui.QApplication.translate("DigitalWindow", "System Parameters", None, QtGui.QApplication.UnicodeUTF8))
+        self.sampleRateLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Sample Rate (sps)", None, QtGui.QApplication.UnicodeUTF8))
         self.rxBox_2.setTitle(QtGui.QApplication.translate("DigitalWindow", "Received Packet Info", None, QtGui.QApplication.UnicodeUTF8))
         self.pktsRcvdLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Packets Rcvd.", None, QtGui.QApplication.UnicodeUTF8))
         self.pktsCorrectLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Packets Correct", None, QtGui.QApplication.UnicodeUTF8))
         self.perLabel.setText(QtGui.QApplication.translate("DigitalWindow", "PER", None, QtGui.QApplication.UnicodeUTF8))
-        self.pauseButton.setText(QtGui.QApplication.translate("DigitalWindow", "Pause", None, QtGui.QApplication.UnicodeUTF8))
-        self.closeButton.setText(QtGui.QApplication.translate("DigitalWindow", "Close", None, QtGui.QApplication.UnicodeUTF8))
         self.menuFile.setTitle(QtGui.QApplication.translate("DigitalWindow", "&File", None, QtGui.QApplication.UnicodeUTF8))
         self.actionExit.setText(QtGui.QApplication.translate("DigitalWindow", "E&xit", None, QtGui.QApplication.UnicodeUTF8))
 
diff --git a/gnuradio-examples/python/digital/qt_digital_window.ui b/gnuradio-examples/python/digital/qt_digital_window.ui
index 413801ec7..a0af196ed 100644
--- a/gnuradio-examples/python/digital/qt_digital_window.ui
+++ b/gnuradio-examples/python/digital/qt_digital_window.ui
@@ -1,105 +1,102 @@
-<ui version="4.0" >
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
  <class>DigitalWindow</class>
- <widget class="QMainWindow" name="DigitalWindow" >
-  <property name="geometry" >
+ <widget class="QMainWindow" name="DigitalWindow">
+  <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>1050</width>
-    <height>752</height>
+    <width>1019</width>
+    <height>754</height>
    </rect>
   </property>
-  <property name="windowTitle" >
+  <property name="windowTitle">
    <string>MainWindow</string>
   </property>
-  <widget class="QWidget" name="centralwidget" >
-   <layout class="QGridLayout" name="gridLayout" >
-    <item row="2" column="0" >
-     <layout class="QVBoxLayout" name="verticalLayout_2" >
+  <widget class="QWidget" name="centralwidget">
+   <layout class="QGridLayout" name="gridLayout">
+    <item row="2" column="2">
+     <layout class="QVBoxLayout" name="verticalLayout_3">
       <item>
-       <widget class="QGroupBox" name="sysBox" >
-        <property name="sizePolicy" >
-         <sizepolicy vsizetype="Fixed" hsizetype="Fixed" >
+       <widget class="QGroupBox" name="rxBox">
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
           <horstretch>0</horstretch>
           <verstretch>0</verstretch>
          </sizepolicy>
         </property>
-        <property name="minimumSize" >
+        <property name="minimumSize">
          <size>
-          <width>240</width>
-          <height>60</height>
+          <width>180</width>
+          <height>90</height>
          </size>
         </property>
-        <property name="maximumSize" >
+        <property name="maximumSize">
          <size>
-          <width>240</width>
+          <width>180</width>
           <height>16777215</height>
          </size>
         </property>
-        <property name="title" >
-         <string>System Parameters</string>
+        <property name="title">
+         <string>Receiver Parameters</string>
         </property>
-        <widget class="QWidget" name="formLayoutWidget" >
-         <property name="geometry" >
+        <widget class="QWidget" name="formLayoutWidget_3">
+         <property name="geometry">
           <rect>
            <x>10</x>
            <y>20</y>
-           <width>221</width>
-           <height>31</height>
+           <width>141</width>
+           <height>61</height>
           </rect>
          </property>
-         <layout class="QFormLayout" name="formLayout" >
-          <property name="sizeConstraint" >
+         <layout class="QFormLayout" name="formLayout_3">
+          <property name="sizeConstraint">
            <enum>QLayout::SetFixedSize</enum>
           </property>
-          <property name="verticalSpacing" >
-           <number>20</number>
-          </property>
-          <item row="0" column="1" >
-           <widget class="QLineEdit" name="sampleRateEdit" >
-            <property name="sizePolicy" >
-             <sizepolicy vsizetype="Fixed" hsizetype="Fixed" >
-              <horstretch>0</horstretch>
-              <verstretch>0</verstretch>
-             </sizepolicy>
+          <item row="0" column="0">
+           <widget class="QLabel" name="gainMuLabel">
+            <property name="text">
+             <string>Gain mu</string>
             </property>
-            <property name="minimumSize" >
+           </widget>
+          </item>
+          <item row="1" column="0">
+           <widget class="QLabel" name="alphaLabel">
+            <property name="text">
+             <string>Alpha</string>
+            </property>
+           </widget>
+          </item>
+          <item row="0" column="1">
+           <widget class="QLineEdit" name="gainMuEdit">
+            <property name="minimumSize">
              <size>
-              <width>100</width>
-              <height>26</height>
+              <width>60</width>
+              <height>0</height>
              </size>
             </property>
-            <property name="maximumSize" >
+            <property name="maximumSize">
              <size>
-              <width>100</width>
-              <height>26</height>
+              <width>80</width>
+              <height>16777215</height>
              </size>
             </property>
            </widget>
           </item>
-          <item row="0" column="0" >
-           <widget class="QLabel" name="sampleRateLabel" >
-            <property name="sizePolicy" >
-             <sizepolicy vsizetype="Fixed" hsizetype="Fixed" >
-              <horstretch>0</horstretch>
-              <verstretch>0</verstretch>
-             </sizepolicy>
-            </property>
-            <property name="minimumSize" >
+          <item row="1" column="1">
+           <widget class="QLineEdit" name="alphaEdit">
+            <property name="minimumSize">
              <size>
-              <width>0</width>
-              <height>20</height>
+              <width>60</width>
+              <height>0</height>
              </size>
             </property>
-            <property name="maximumSize" >
+            <property name="maximumSize">
              <size>
-              <width>16777215</width>
-              <height>20</height>
+              <width>80</width>
+              <height>16777215</height>
              </size>
             </property>
-            <property name="text" >
-             <string>Sample Rate (sps)</string>
-            </property>
            </widget>
           </item>
          </layout>
@@ -107,14 +104,53 @@
        </widget>
       </item>
       <item>
-       <spacer name="verticalSpacer_2" >
-        <property name="orientation" >
+       <spacer name="verticalSpacer_4">
+        <property name="orientation">
          <enum>Qt::Vertical</enum>
         </property>
-        <property name="sizeType" >
+        <property name="sizeType">
          <enum>QSizePolicy::Fixed</enum>
         </property>
-        <property name="sizeHint" stdset="0" >
+        <property name="sizeHint" stdset="0">
+         <size>
+          <width>20</width>
+          <height>30</height>
+         </size>
+        </property>
+       </spacer>
+      </item>
+     </layout>
+    </item>
+    <item row="2" column="5">
+     <layout class="QVBoxLayout" name="verticalLayout">
+      <item>
+       <widget class="QPushButton" name="pauseButton">
+        <property name="minimumSize">
+         <size>
+          <width>80</width>
+          <height>0</height>
+         </size>
+        </property>
+        <property name="maximumSize">
+         <size>
+          <width>80</width>
+          <height>16777215</height>
+         </size>
+        </property>
+        <property name="text">
+         <string>Pause</string>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <spacer name="verticalSpacer">
+        <property name="orientation">
+         <enum>Qt::Vertical</enum>
+        </property>
+        <property name="sizeType">
+         <enum>QSizePolicy::Fixed</enum>
+        </property>
+        <property name="sizeHint" stdset="0">
          <size>
           <width>20</width>
           <height>60</height>
@@ -122,111 +158,130 @@
         </property>
        </spacer>
       </item>
+      <item>
+       <widget class="QPushButton" name="closeButton">
+        <property name="minimumSize">
+         <size>
+          <width>80</width>
+          <height>0</height>
+         </size>
+        </property>
+        <property name="maximumSize">
+         <size>
+          <width>80</width>
+          <height>16777215</height>
+         </size>
+        </property>
+        <property name="text">
+         <string>Close</string>
+        </property>
+       </widget>
+      </item>
      </layout>
     </item>
-    <item row="2" column="1" >
-     <widget class="QGroupBox" name="channelModeBox" >
-      <property name="sizePolicy" >
-       <sizepolicy vsizetype="Fixed" hsizetype="Fixed" >
+    <item row="2" column="1">
+     <widget class="QGroupBox" name="channelModeBox">
+      <property name="sizePolicy">
+       <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
         <horstretch>0</horstretch>
         <verstretch>0</verstretch>
        </sizepolicy>
       </property>
-      <property name="minimumSize" >
+      <property name="minimumSize">
        <size>
         <width>245</width>
         <height>130</height>
        </size>
       </property>
-      <property name="maximumSize" >
+      <property name="maximumSize">
        <size>
         <width>245</width>
         <height>16777215</height>
        </size>
       </property>
-      <property name="title" >
+      <property name="title">
        <string>Channel Model Parameters</string>
       </property>
-      <widget class="QWidget" name="formLayoutWidget_2" >
-       <property name="geometry" >
+      <widget class="QWidget" name="formLayoutWidget_2">
+       <property name="geometry">
         <rect>
          <x>10</x>
          <y>20</y>
-         <width>231</width>
+         <width>221</width>
          <height>98</height>
         </rect>
        </property>
-       <layout class="QFormLayout" name="formLayout_2" >
-        <property name="sizeConstraint" >
+       <layout class="QFormLayout" name="formLayout_2">
+        <property name="sizeConstraint">
          <enum>QLayout::SetFixedSize</enum>
         </property>
-        <property name="fieldGrowthPolicy" >
+        <property name="fieldGrowthPolicy">
          <enum>QFormLayout::AllNonFixedFieldsGrow</enum>
         </property>
-        <item row="0" column="0" >
-         <widget class="QLabel" name="snrLabel" >
-          <property name="text" >
+        <item row="0" column="0">
+         <widget class="QLabel" name="snrLabel">
+          <property name="text">
            <string>SNR (dB)</string>
           </property>
          </widget>
         </item>
-        <item row="0" column="1" >
-         <widget class="QLineEdit" name="snrEdit" >
-          <property name="minimumSize" >
+        <item row="0" column="1">
+         <widget class="QLineEdit" name="snrEdit">
+          <property name="minimumSize">
            <size>
-            <width>100</width>
+            <width>60</width>
             <height>0</height>
            </size>
           </property>
-          <property name="maximumSize" >
+          <property name="maximumSize">
            <size>
-            <width>100</width>
+            <width>80</width>
             <height>16777215</height>
            </size>
           </property>
          </widget>
         </item>
-        <item row="1" column="0" >
-         <widget class="QLabel" name="freqLabel" >
-          <property name="text" >
+        <item row="1" column="0">
+         <widget class="QLabel" name="freqLabel">
+          <property name="text">
            <string>Frequency Offset (Hz)</string>
           </property>
          </widget>
         </item>
-        <item row="1" column="1" >
-         <widget class="QLineEdit" name="freqEdit" >
-          <property name="minimumSize" >
+        <item row="1" column="1">
+         <widget class="QLineEdit" name="freqEdit">
+          <property name="minimumSize">
            <size>
-            <width>100</width>
+            <width>60</width>
             <height>0</height>
            </size>
           </property>
-          <property name="maximumSize" >
+          <property name="maximumSize">
            <size>
-            <width>100</width>
+            <width>80</width>
             <height>16777215</height>
            </size>
           </property>
          </widget>
         </item>
-        <item row="2" column="0" >
-         <widget class="QLabel" name="timeLabel" >
-          <property name="text" >
+        <item row="2" column="0">
+         <widget class="QLabel" name="timeLabel">
+          <property name="text">
            <string>Timing Offset</string>
           </property>
          </widget>
         </item>
-        <item row="2" column="1" >
-         <widget class="QLineEdit" name="timeEdit" >
-          <property name="minimumSize" >
+        <item row="2" column="1">
+         <widget class="QLineEdit" name="timeEdit">
+          <property name="minimumSize">
            <size>
-            <width>100</width>
+            <width>60</width>
             <height>0</height>
            </size>
           </property>
-          <property name="maximumSize" >
+          <property name="maximumSize">
            <size>
-            <width>100</width>
+            <width>80</width>
             <height>16777215</height>
            </size>
           </property>
@@ -236,121 +291,92 @@
       </widget>
      </widget>
     </item>
-    <item row="0" column="0" colspan="6" >
-     <layout class="QVBoxLayout" name="verticalLayout_5" >
-      <item>
-       <widget class="QFrame" name="sinkFrame" >
-        <property name="sizePolicy" >
-         <sizepolicy vsizetype="Expanding" hsizetype="Expanding" >
-          <horstretch>0</horstretch>
-          <verstretch>0</verstretch>
-         </sizepolicy>
-        </property>
-        <property name="minimumSize" >
-         <size>
-          <width>1000</width>
-          <height>550</height>
-         </size>
-        </property>
-        <property name="frameShape" >
-         <enum>QFrame::StyledPanel</enum>
-        </property>
-        <property name="frameShadow" >
-         <enum>QFrame::Raised</enum>
-        </property>
-        <layout class="QGridLayout" name="gridLayout_2" >
-         <item row="1" column="0" >
-          <layout class="QHBoxLayout" name="sinkLayout" />
-         </item>
-        </layout>
-        <zorder>verticalLayoutWidget</zorder>
-        <zorder>verticalLayoutWidget</zorder>
-       </widget>
-      </item>
-     </layout>
-    </item>
-    <item row="2" column="2" >
-     <layout class="QVBoxLayout" name="verticalLayout_3" >
+    <item row="2" column="0">
+     <layout class="QVBoxLayout" name="verticalLayout_2">
       <item>
-       <widget class="QGroupBox" name="rxBox" >
-        <property name="sizePolicy" >
-         <sizepolicy vsizetype="Fixed" hsizetype="Fixed" >
+       <widget class="QGroupBox" name="sysBox">
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
           <horstretch>0</horstretch>
           <verstretch>0</verstretch>
          </sizepolicy>
         </property>
-        <property name="minimumSize" >
+        <property name="minimumSize">
          <size>
-          <width>180</width>
-          <height>90</height>
+          <width>240</width>
+          <height>60</height>
          </size>
         </property>
-        <property name="maximumSize" >
+        <property name="maximumSize">
          <size>
-          <width>180</width>
+          <width>240</width>
           <height>16777215</height>
          </size>
         </property>
-        <property name="title" >
-         <string>Receiver Parameters</string>
+        <property name="title">
+         <string>System Parameters</string>
         </property>
-        <widget class="QWidget" name="formLayoutWidget_3" >
-         <property name="geometry" >
+        <widget class="QWidget" name="formLayoutWidget">
+         <property name="geometry">
           <rect>
            <x>10</x>
            <y>20</y>
-           <width>161</width>
-           <height>61</height>
+           <width>211</width>
+           <height>31</height>
           </rect>
          </property>
-         <layout class="QFormLayout" name="formLayout_3" >
-          <property name="sizeConstraint" >
+         <layout class="QFormLayout" name="formLayout">
+          <property name="sizeConstraint">
            <enum>QLayout::SetFixedSize</enum>
           </property>
-          <item row="0" column="0" >
-           <widget class="QLabel" name="gainMuLabel" >
-            <property name="text" >
-             <string>Gain mu</string>
-            </property>
-           </widget>
-          </item>
-          <item row="1" column="0" >
-           <widget class="QLabel" name="alphaLabel" >
-            <property name="text" >
-             <string>Alpha</string>
+          <property name="verticalSpacing">
+           <number>20</number>
+          </property>
+          <item row="0" column="1">
+           <widget class="QLineEdit" name="sampleRateEdit">
+            <property name="sizePolicy">
+             <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
+              <horstretch>0</horstretch>
+              <verstretch>0</verstretch>
+             </sizepolicy>
             </property>
-           </widget>
-          </item>
-          <item row="0" column="1" >
-           <widget class="QLineEdit" name="gainMuEdit" >
-            <property name="minimumSize" >
+            <property name="minimumSize">
              <size>
-              <width>100</width>
-              <height>0</height>
+              <width>60</width>
+              <height>26</height>
              </size>
             </property>
-            <property name="maximumSize" >
+            <property name="maximumSize">
              <size>
-              <width>100</width>
-              <height>16777215</height>
+              <width>80</width>
+              <height>26</height>
              </size>
             </property>
            </widget>
           </item>
-          <item row="1" column="1" >
-           <widget class="QLineEdit" name="alphaEdit" >
-            <property name="minimumSize" >
+          <item row="0" column="0">
+           <widget class="QLabel" name="sampleRateLabel">
+            <property name="sizePolicy">
+             <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
+              <horstretch>0</horstretch>
+              <verstretch>0</verstretch>
+             </sizepolicy>
+            </property>
+            <property name="minimumSize">
              <size>
-              <width>100</width>
-              <height>0</height>
+              <width>0</width>
+              <height>20</height>
              </size>
             </property>
-            <property name="maximumSize" >
+            <property name="maximumSize">
              <size>
-              <width>100</width>
-              <height>16777215</height>
+              <width>16777215</width>
+              <height>20</height>
              </size>
             </property>
+            <property name="text">
+             <string>Sample Rate (sps)</string>
+            </property>
            </widget>
           </item>
          </layout>
@@ -358,123 +384,123 @@
        </widget>
       </item>
       <item>
-       <spacer name="verticalSpacer_4" >
-        <property name="orientation" >
+       <spacer name="verticalSpacer_2">
+        <property name="orientation">
          <enum>Qt::Vertical</enum>
         </property>
-        <property name="sizeType" >
+        <property name="sizeType">
          <enum>QSizePolicy::Fixed</enum>
         </property>
-        <property name="sizeHint" stdset="0" >
+        <property name="sizeHint" stdset="0">
          <size>
           <width>20</width>
-          <height>30</height>
+          <height>60</height>
          </size>
         </property>
        </spacer>
       </item>
      </layout>
     </item>
-    <item row="2" column="3" >
-     <widget class="QGroupBox" name="rxBox_2" >
-      <property name="sizePolicy" >
-       <sizepolicy vsizetype="Fixed" hsizetype="Fixed" >
+    <item row="2" column="3">
+     <widget class="QGroupBox" name="rxBox_2">
+      <property name="sizePolicy">
+       <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
         <horstretch>0</horstretch>
         <verstretch>0</verstretch>
        </sizepolicy>
       </property>
-      <property name="minimumSize" >
+      <property name="minimumSize">
        <size>
         <width>220</width>
         <height>125</height>
        </size>
       </property>
-      <property name="maximumSize" >
+      <property name="maximumSize">
        <size>
         <width>265</width>
         <height>125</height>
        </size>
       </property>
-      <property name="title" >
+      <property name="title">
        <string>Received Packet Info</string>
       </property>
-      <widget class="QWidget" name="formLayoutWidget_4" >
-       <property name="geometry" >
+      <widget class="QWidget" name="formLayoutWidget_4">
+       <property name="geometry">
         <rect>
          <x>10</x>
          <y>20</y>
-         <width>201</width>
+         <width>181</width>
          <height>92</height>
         </rect>
        </property>
-       <layout class="QFormLayout" name="formLayout_4" >
-        <property name="sizeConstraint" >
+       <layout class="QFormLayout" name="formLayout_4">
+        <property name="sizeConstraint">
          <enum>QLayout::SetFixedSize</enum>
         </property>
-        <item row="0" column="0" >
-         <widget class="QLabel" name="pktsRcvdLabel" >
-          <property name="text" >
+        <item row="0" column="0">
+         <widget class="QLabel" name="pktsRcvdLabel">
+          <property name="text">
            <string>Packets Rcvd.</string>
           </property>
          </widget>
         </item>
-        <item row="1" column="0" >
-         <widget class="QLabel" name="pktsCorrectLabel" >
-          <property name="text" >
+        <item row="1" column="0">
+         <widget class="QLabel" name="pktsCorrectLabel">
+          <property name="text">
            <string>Packets Correct</string>
           </property>
          </widget>
         </item>
-        <item row="2" column="0" >
-         <widget class="QLabel" name="perLabel" >
-          <property name="text" >
+        <item row="2" column="0">
+         <widget class="QLabel" name="perLabel">
+          <property name="text">
            <string>PER</string>
           </property>
          </widget>
         </item>
-        <item row="0" column="1" >
-         <widget class="QLineEdit" name="pktsRcvdEdit" >
-          <property name="minimumSize" >
+        <item row="0" column="1">
+         <widget class="QLineEdit" name="pktsRcvdEdit">
+          <property name="minimumSize">
            <size>
-            <width>100</width>
+            <width>60</width>
             <height>0</height>
            </size>
           </property>
-          <property name="maximumSize" >
+          <property name="maximumSize">
            <size>
-            <width>100</width>
+            <width>80</width>
             <height>16777215</height>
            </size>
           </property>
          </widget>
         </item>
-        <item row="1" column="1" >
-         <widget class="QLineEdit" name="pktsCorrectEdit" >
-          <property name="minimumSize" >
+        <item row="1" column="1">
+         <widget class="QLineEdit" name="pktsCorrectEdit">
+          <property name="minimumSize">
            <size>
-            <width>100</width>
+            <width>60</width>
             <height>0</height>
            </size>
           </property>
-          <property name="maximumSize" >
+          <property name="maximumSize">
            <size>
-            <width>100</width>
+            <width>80</width>
             <height>16777215</height>
            </size>
           </property>
          </widget>
         </item>
-        <item row="2" column="1" >
-         <widget class="QLineEdit" name="perEdit" >
-          <property name="minimumSize" >
+        <item row="2" column="1">
+         <widget class="QLineEdit" name="perEdit">
+          <property name="minimumSize">
            <size>
-            <width>100</width>
+            <width>60</width>
             <height>0</height>
            </size>
           </property>
-          <property name="maximumSize" >
+          <property name="maximumSize">
            <size>
-            <width>100</width>
+            <width>80</width>
             <height>16777215</height>
            </size>
           </property>
@@ -484,12 +510,12 @@
       </widget>
      </widget>
     </item>
-    <item row="2" column="4" >
-     <spacer name="horizontalSpacer" >
-      <property name="orientation" >
+    <item row="2" column="4">
+     <spacer name="horizontalSpacer">
+      <property name="orientation">
        <enum>Qt::Horizontal</enum>
       </property>
-      <property name="sizeHint" stdset="0" >
+      <property name="sizeHint" stdset="0">
        <size>
         <width>20</width>
         <height>20</height>
@@ -497,95 +523,64 @@
       </property>
      </spacer>
     </item>
-    <item row="2" column="5" >
-     <layout class="QVBoxLayout" name="verticalLayout" >
+    <item row="0" column="0" colspan="6">
+     <layout class="QVBoxLayout" name="verticalLayout_5">
       <item>
-       <widget class="QPushButton" name="pauseButton" >
-        <property name="minimumSize" >
-         <size>
-          <width>80</width>
-          <height>0</height>
-         </size>
-        </property>
-        <property name="maximumSize" >
-         <size>
-          <width>80</width>
-          <height>16777215</height>
-         </size>
-        </property>
-        <property name="text" >
-         <string>Pause</string>
-        </property>
-       </widget>
-      </item>
-      <item>
-       <spacer name="verticalSpacer" >
-        <property name="orientation" >
-         <enum>Qt::Vertical</enum>
-        </property>
-        <property name="sizeType" >
-         <enum>QSizePolicy::Fixed</enum>
-        </property>
-        <property name="sizeHint" stdset="0" >
-         <size>
-          <width>20</width>
-          <height>60</height>
-         </size>
+       <widget class="QFrame" name="sinkFrame">
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="Expanding" vsizetype="Expanding">
+          <horstretch>0</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
         </property>
-       </spacer>
-      </item>
-      <item>
-       <widget class="QPushButton" name="closeButton" >
-        <property name="minimumSize" >
+        <property name="minimumSize">
          <size>
-          <width>80</width>
-          <height>0</height>
+          <width>500</width>
+          <height>550</height>
          </size>
         </property>
-        <property name="maximumSize" >
-         <size>
-          <width>80</width>
-          <height>16777215</height>
-         </size>
+        <property name="frameShape">
+         <enum>QFrame::StyledPanel</enum>
         </property>
-        <property name="text" >
-         <string>Close</string>
+        <property name="frameShadow">
+         <enum>QFrame::Raised</enum>
         </property>
+        <layout class="QGridLayout" name="gridLayout_2">
+         <item row="1" column="0">
+          <layout class="QHBoxLayout" name="sinkLayout"/>
+         </item>
+        </layout>
        </widget>
       </item>
      </layout>
     </item>
    </layout>
-   <zorder>sinkFrame</zorder>
    <zorder>channelModeBox</zorder>
-   <zorder>verticalLayoutWidget</zorder>
-   <zorder>verticalLayoutWidget</zorder>
-   <zorder>rxBox</zorder>
    <zorder></zorder>
    <zorder>rxBox_2</zorder>
    <zorder>horizontalSpacer</zorder>
    <zorder></zorder>
   </widget>
-  <widget class="QMenuBar" name="menubar" >
-   <property name="geometry" >
+  <widget class="QMenuBar" name="menubar">
+   <property name="geometry">
     <rect>
      <x>0</x>
      <y>0</y>
-     <width>1050</width>
-     <height>24</height>
+     <width>1019</width>
+     <height>25</height>
     </rect>
    </property>
-   <widget class="QMenu" name="menuFile" >
-    <property name="title" >
+   <widget class="QMenu" name="menuFile">
+    <property name="title">
      <string>&amp;File</string>
     </property>
-    <addaction name="actionExit" />
+    <addaction name="actionExit"/>
    </widget>
-   <addaction name="menuFile" />
+   <addaction name="menuFile"/>
   </widget>
-  <widget class="QStatusBar" name="statusbar" />
-  <action name="actionExit" >
-   <property name="text" >
+  <widget class="QStatusBar" name="statusbar"/>
+  <action name="actionExit">
+   <property name="text">
     <string>E&amp;xit</string>
    </property>
   </action>
@@ -603,11 +598,11 @@
    <receiver>DigitalWindow</receiver>
    <slot>close()</slot>
    <hints>
-    <hint type="sourcelabel" >
+    <hint type="sourcelabel">
      <x>322</x>
      <y>623</y>
     </hint>
-    <hint type="destinationlabel" >
+    <hint type="destinationlabel">
      <x>66</x>
      <y>561</y>
     </hint>
@@ -619,11 +614,11 @@
    <receiver>DigitalWindow</receiver>
    <slot>close()</slot>
    <hints>
-    <hint type="sourcelabel" >
+    <hint type="sourcelabel">
      <x>-1</x>
      <y>-1</y>
     </hint>
-    <hint type="destinationlabel" >
+    <hint type="destinationlabel">
      <x>617</x>
      <y>327</y>
     </hint>
diff --git a/gnuradio-examples/python/digital/qt_digital_window2.py b/gnuradio-examples/python/digital/qt_digital_window2.py
new file mode 100644
index 000000000..f111e3772
--- /dev/null
+++ b/gnuradio-examples/python/digital/qt_digital_window2.py
@@ -0,0 +1,261 @@
+# -*- coding: utf-8 -*-
+
+# Form implementation generated from reading ui file 'qt_digital_window.ui'
+#
+# Created: Mon Oct 12 12:10:54 2009
+#      by: PyQt4 UI code generator 4.4.3
+#
+# WARNING! All changes made in this file will be lost!
+
+from PyQt4 import QtCore, QtGui
+
+class Ui_DigitalWindow(object):
+    def setupUi(self, DigitalWindow):
+        DigitalWindow.setObjectName("DigitalWindow")
+        DigitalWindow.resize(1019, 754)
+        self.centralwidget = QtGui.QWidget(DigitalWindow)
+        self.centralwidget.setObjectName("centralwidget")
+        self.gridLayout = QtGui.QGridLayout(self.centralwidget)
+        self.gridLayout.setObjectName("gridLayout")
+        self.verticalLayout_2 = QtGui.QVBoxLayout()
+        self.verticalLayout_2.setObjectName("verticalLayout_2")
+        self.sysBox = QtGui.QGroupBox(self.centralwidget)
+        sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(self.sysBox.sizePolicy().hasHeightForWidth())
+        self.sysBox.setSizePolicy(sizePolicy)
+        self.sysBox.setMinimumSize(QtCore.QSize(240, 60))
+        self.sysBox.setMaximumSize(QtCore.QSize(240, 16777215))
+        self.sysBox.setObjectName("sysBox")
+        self.formLayoutWidget = QtGui.QWidget(self.sysBox)
+        self.formLayoutWidget.setGeometry(QtCore.QRect(10, 20, 211, 31))
+        self.formLayoutWidget.setObjectName("formLayoutWidget")
+        self.formLayout = QtGui.QFormLayout(self.formLayoutWidget)
+        self.formLayout.setSizeConstraint(QtGui.QLayout.SetFixedSize)
+        self.formLayout.setVerticalSpacing(20)
+        self.formLayout.setObjectName("formLayout")
+        self.sampleRateEdit = QtGui.QLineEdit(self.formLayoutWidget)
+        sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(self.sampleRateEdit.sizePolicy().hasHeightForWidth())
+        self.sampleRateEdit.setSizePolicy(sizePolicy)
+        self.sampleRateEdit.setMinimumSize(QtCore.QSize(60, 26))
+        self.sampleRateEdit.setMaximumSize(QtCore.QSize(80, 26))
+        self.sampleRateEdit.setObjectName("sampleRateEdit")
+        self.formLayout.setWidget(0, QtGui.QFormLayout.FieldRole, self.sampleRateEdit)
+        self.sampleRateLabel = QtGui.QLabel(self.formLayoutWidget)
+        sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(self.sampleRateLabel.sizePolicy().hasHeightForWidth())
+        self.sampleRateLabel.setSizePolicy(sizePolicy)
+        self.sampleRateLabel.setMinimumSize(QtCore.QSize(0, 20))
+        self.sampleRateLabel.setMaximumSize(QtCore.QSize(16777215, 20))
+        self.sampleRateLabel.setObjectName("sampleRateLabel")
+        self.formLayout.setWidget(0, QtGui.QFormLayout.LabelRole, self.sampleRateLabel)
+        self.verticalLayout_2.addWidget(self.sysBox)
+        spacerItem = QtGui.QSpacerItem(20, 60, QtGui.QSizePolicy.Minimum, QtGui.QSizePolicy.Fixed)
+        self.verticalLayout_2.addItem(spacerItem)
+        self.gridLayout.addLayout(self.verticalLayout_2, 2, 0, 1, 1)
+        self.verticalLayout_5 = QtGui.QVBoxLayout()
+        self.verticalLayout_5.setObjectName("verticalLayout_5")
+        self.sinkFrame = QtGui.QFrame(self.centralwidget)
+        sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Expanding, QtGui.QSizePolicy.Expanding)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(self.sinkFrame.sizePolicy().hasHeightForWidth())
+        self.sinkFrame.setSizePolicy(sizePolicy)
+        self.sinkFrame.setMinimumSize(QtCore.QSize(500, 550))
+        self.sinkFrame.setFrameShape(QtGui.QFrame.StyledPanel)
+        self.sinkFrame.setFrameShadow(QtGui.QFrame.Raised)
+        self.sinkFrame.setObjectName("sinkFrame")
+        self.gridLayout_2 = QtGui.QGridLayout(self.sinkFrame)
+        self.gridLayout_2.setObjectName("gridLayout_2")
+        self.sinkLayout = QtGui.QHBoxLayout()
+        self.sinkLayout.setObjectName("sinkLayout")
+        self.gridLayout_2.addLayout(self.sinkLayout, 1, 0, 1, 1)
+        self.verticalLayout_5.addWidget(self.sinkFrame)
+        self.gridLayout.addLayout(self.verticalLayout_5, 0, 0, 1, 6)
+        self.channelModeBox = QtGui.QGroupBox(self.centralwidget)
+        sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(self.channelModeBox.sizePolicy().hasHeightForWidth())
+        self.channelModeBox.setSizePolicy(sizePolicy)
+        self.channelModeBox.setMinimumSize(QtCore.QSize(245, 130))
+        self.channelModeBox.setMaximumSize(QtCore.QSize(245, 16777215))
+        self.channelModeBox.setObjectName("channelModeBox")
+        self.formLayoutWidget_2 = QtGui.QWidget(self.channelModeBox)
+        self.formLayoutWidget_2.setGeometry(QtCore.QRect(10, 20, 221, 98))
+        self.formLayoutWidget_2.setObjectName("formLayoutWidget_2")
+        self.formLayout_2 = QtGui.QFormLayout(self.formLayoutWidget_2)
+        self.formLayout_2.setSizeConstraint(QtGui.QLayout.SetFixedSize)
+        self.formLayout_2.setFieldGrowthPolicy(QtGui.QFormLayout.AllNonFixedFieldsGrow)
+        self.formLayout_2.setObjectName("formLayout_2")
+        self.snrLabel = QtGui.QLabel(self.formLayoutWidget_2)
+        self.snrLabel.setObjectName("snrLabel")
+        self.formLayout_2.setWidget(0, QtGui.QFormLayout.LabelRole, self.snrLabel)
+        self.snrEdit = QtGui.QLineEdit(self.formLayoutWidget_2)
+        self.snrEdit.setMinimumSize(QtCore.QSize(60, 0))
+        self.snrEdit.setMaximumSize(QtCore.QSize(80, 16777215))
+        self.snrEdit.setObjectName("snrEdit")
+        self.formLayout_2.setWidget(0, QtGui.QFormLayout.FieldRole, self.snrEdit)
+        self.freqLabel = QtGui.QLabel(self.formLayoutWidget_2)
+        self.freqLabel.setObjectName("freqLabel")
+        self.formLayout_2.setWidget(1, QtGui.QFormLayout.LabelRole, self.freqLabel)
+        self.freqEdit = QtGui.QLineEdit(self.formLayoutWidget_2)
+        self.freqEdit.setMinimumSize(QtCore.QSize(60, 0))
+        self.freqEdit.setMaximumSize(QtCore.QSize(80, 16777215))
+        self.freqEdit.setObjectName("freqEdit")
+        self.formLayout_2.setWidget(1, QtGui.QFormLayout.FieldRole, self.freqEdit)
+        self.timeLabel = QtGui.QLabel(self.formLayoutWidget_2)
+        self.timeLabel.setObjectName("timeLabel")
+        self.formLayout_2.setWidget(2, QtGui.QFormLayout.LabelRole, self.timeLabel)
+        self.timeEdit = QtGui.QLineEdit(self.formLayoutWidget_2)
+        self.timeEdit.setMinimumSize(QtCore.QSize(60, 0))
+        self.timeEdit.setMaximumSize(QtCore.QSize(80, 16777215))
+        self.timeEdit.setObjectName("timeEdit")
+        self.formLayout_2.setWidget(2, QtGui.QFormLayout.FieldRole, self.timeEdit)
+        self.gridLayout.addWidget(self.channelModeBox, 2, 1, 1, 1)
+        self.rxBox_2 = QtGui.QGroupBox(self.centralwidget)
+        sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(self.rxBox_2.sizePolicy().hasHeightForWidth())
+        self.rxBox_2.setSizePolicy(sizePolicy)
+        self.rxBox_2.setMinimumSize(QtCore.QSize(220, 125))
+        self.rxBox_2.setMaximumSize(QtCore.QSize(265, 125))
+        self.rxBox_2.setObjectName("rxBox_2")
+        self.formLayoutWidget_4 = QtGui.QWidget(self.rxBox_2)
+        self.formLayoutWidget_4.setGeometry(QtCore.QRect(10, 20, 248, 188))
+        self.formLayoutWidget_4.setObjectName("formLayoutWidget_4")
+        self.formLayout_4 = QtGui.QFormLayout(self.formLayoutWidget_4)
+        self.formLayout_4.setSizeConstraint(QtGui.QLayout.SetFixedSize)
+        self.formLayout_4.setFieldGrowthPolicy(QtGui.QFormLayout.AllNonFixedFieldsGrow)
+        self.formLayout_4.setObjectName("formLayout_4")
+        self.pktsRcvdLabel = QtGui.QLabel(self.formLayoutWidget_4)
+        self.pktsRcvdLabel.setObjectName("pktsRcvdLabel")
+        self.formLayout_4.setWidget(0, QtGui.QFormLayout.LabelRole, self.pktsRcvdLabel)
+        self.pktsRcvdEdit = QtGui.QLineEdit(self.formLayoutWidget_4)
+        self.pktsRcvdEdit.setMinimumSize(QtCore.QSize(60, 0))
+        self.pktsRcvdEdit.setMaximumSize(QtCore.QSize(80, 16777215))
+        self.pktsRcvdEdit.setObjectName("pktsRcvdEdit")
+        self.formLayout_4.setWidget(0, QtGui.QFormLayout.FieldRole, self.pktsRcvdEdit)
+        self.pktsCorrectLabel = QtGui.QLabel(self.formLayoutWidget_4)
+        self.pktsCorrectLabel.setObjectName("pktsCorrectLabel")
+        self.formLayout_4.setWidget(1, QtGui.QFormLayout.LabelRole, self.pktsCorrectLabel)
+        self.pktsCorrectEdit = QtGui.QLineEdit(self.formLayoutWidget_4)
+        self.pktsCorrectEdit.setMinimumSize(QtCore.QSize(60, 0))
+        self.pktsCorrectEdit.setMaximumSize(QtCore.QSize(80, 16777215))
+        self.pktsCorrectEdit.setObjectName("pktsCorrectEdit")
+        self.formLayout_4.setWidget(1, QtGui.QFormLayout.FieldRole, self.pktsCorrectEdit)
+        self.perLabel = QtGui.QLabel(self.formLayoutWidget_4)
+        self.perLabel.setObjectName("perLabel")
+        self.formLayout_4.setWidget(2, QtGui.QFormLayout.LabelRole, self.perLabel)
+        self.perEdit = QtGui.QLineEdit(self.formLayoutWidget_4)
+        self.perEdit.setMinimumSize(QtCore.QSize(60, 0))
+        self.perEdit.setMaximumSize(QtCore.QSize(80, 16777215))
+        self.perEdit.setObjectName("perEdit")
+        self.formLayout_4.setWidget(2, QtGui.QFormLayout.FieldRole, self.perEdit)
+        self.gridLayout.addWidget(self.rxBox_2, 2, 3, 1, 1)
+        spacerItem1 = QtGui.QSpacerItem(20, 20, QtGui.QSizePolicy.Expanding, QtGui.QSizePolicy.Minimum)
+        self.gridLayout.addItem(spacerItem1, 2, 4, 1, 1)
+        self.verticalLayout = QtGui.QVBoxLayout()
+        self.verticalLayout.setObjectName("verticalLayout")
+        self.pauseButton = QtGui.QPushButton(self.centralwidget)
+        self.pauseButton.setMinimumSize(QtCore.QSize(80, 0))
+        self.pauseButton.setMaximumSize(QtCore.QSize(80, 16777215))
+        self.pauseButton.setObjectName("pauseButton")
+        self.verticalLayout.addWidget(self.pauseButton)
+        spacerItem2 = QtGui.QSpacerItem(20, 60, QtGui.QSizePolicy.Minimum, QtGui.QSizePolicy.Fixed)
+        self.verticalLayout.addItem(spacerItem2)
+        self.closeButton = QtGui.QPushButton(self.centralwidget)
+        self.closeButton.setMinimumSize(QtCore.QSize(80, 0))
+        self.closeButton.setMaximumSize(QtCore.QSize(80, 16777215))
+        self.closeButton.setObjectName("closeButton")
+        self.verticalLayout.addWidget(self.closeButton)
+        self.gridLayout.addLayout(self.verticalLayout, 2, 5, 1, 1)
+        self.rxBox = QtGui.QGroupBox(self.centralwidget)
+        sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed, QtGui.QSizePolicy.Fixed)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(self.rxBox.sizePolicy().hasHeightForWidth())
+        self.rxBox.setSizePolicy(sizePolicy)
+        self.rxBox.setMinimumSize(QtCore.QSize(180, 120))
+        self.rxBox.setMaximumSize(QtCore.QSize(180, 16777215))
+        self.rxBox.setObjectName("rxBox")
+        self.formLayoutWidget_3 = QtGui.QWidget(self.rxBox)
+        self.formLayoutWidget_3.setGeometry(QtCore.QRect(10, 10, 161, 101))
+        self.formLayoutWidget_3.setObjectName("formLayoutWidget_3")
+        self.formLayout_3 = QtGui.QFormLayout(self.formLayoutWidget_3)
+        self.formLayout_3.setSizeConstraint(QtGui.QLayout.SetFixedSize)
+        self.formLayout_3.setObjectName("formLayout_3")
+        self.alphaTimeLabel = QtGui.QLabel(self.formLayoutWidget_3)
+        self.alphaTimeLabel.setObjectName("alphaTimeLabel")
+        self.formLayout_3.setWidget(0, QtGui.QFormLayout.LabelRole, self.alphaTimeLabel)
+        self.alphaFreqLabel = QtGui.QLabel(self.formLayoutWidget_3)
+        self.alphaFreqLabel.setObjectName("alphaFreqLabel")
+        self.formLayout_3.setWidget(2, QtGui.QFormLayout.LabelRole, self.alphaFreqLabel)
+        self.alphaTimeEdit = QtGui.QLineEdit(self.formLayoutWidget_3)
+        self.alphaTimeEdit.setMinimumSize(QtCore.QSize(60, 0))
+        self.alphaTimeEdit.setMaximumSize(QtCore.QSize(80, 16777215))
+        self.alphaTimeEdit.setObjectName("alphaTimeEdit")
+        self.formLayout_3.setWidget(0, QtGui.QFormLayout.FieldRole, self.alphaTimeEdit)
+        self.alphaFreqEdit = QtGui.QLineEdit(self.formLayoutWidget_3)
+        self.alphaFreqEdit.setMinimumSize(QtCore.QSize(60, 0))
+        self.alphaFreqEdit.setMaximumSize(QtCore.QSize(80, 16777215))
+        self.alphaFreqEdit.setObjectName("alphaFreqEdit")
+        self.formLayout_3.setWidget(2, QtGui.QFormLayout.FieldRole, self.alphaFreqEdit)
+        self.betaTimeEdit = QtGui.QLineEdit(self.formLayoutWidget_3)
+        self.betaTimeEdit.setMaximumSize(QtCore.QSize(80, 16777215))
+        self.betaTimeEdit.setObjectName("betaTimeEdit")
+        self.formLayout_3.setWidget(1, QtGui.QFormLayout.FieldRole, self.betaTimeEdit)
+        self.betaTimeLabel = QtGui.QLabel(self.formLayoutWidget_3)
+        self.betaTimeLabel.setObjectName("betaTimeLabel")
+        self.formLayout_3.setWidget(1, QtGui.QFormLayout.LabelRole, self.betaTimeLabel)
+        self.gridLayout.addWidget(self.rxBox, 2, 2, 1, 1)
+        DigitalWindow.setCentralWidget(self.centralwidget)
+        self.menubar = QtGui.QMenuBar(DigitalWindow)
+        self.menubar.setGeometry(QtCore.QRect(0, 0, 1019, 24))
+        self.menubar.setObjectName("menubar")
+        self.menuFile = QtGui.QMenu(self.menubar)
+        self.menuFile.setObjectName("menuFile")
+        DigitalWindow.setMenuBar(self.menubar)
+        self.statusbar = QtGui.QStatusBar(DigitalWindow)
+        self.statusbar.setObjectName("statusbar")
+        DigitalWindow.setStatusBar(self.statusbar)
+        self.actionExit = QtGui.QAction(DigitalWindow)
+        self.actionExit.setObjectName("actionExit")
+        self.menuFile.addAction(self.actionExit)
+        self.menubar.addAction(self.menuFile.menuAction())
+
+        self.retranslateUi(DigitalWindow)
+        QtCore.QObject.connect(self.closeButton, QtCore.SIGNAL("clicked()"), DigitalWindow.close)
+        QtCore.QObject.connect(self.actionExit, QtCore.SIGNAL("triggered()"), DigitalWindow.close)
+        QtCore.QMetaObject.connectSlotsByName(DigitalWindow)
+        DigitalWindow.setTabOrder(self.snrEdit, self.freqEdit)
+        DigitalWindow.setTabOrder(self.freqEdit, self.timeEdit)
+
+    def retranslateUi(self, DigitalWindow):
+        DigitalWindow.setWindowTitle(QtGui.QApplication.translate("DigitalWindow", "MainWindow", None, QtGui.QApplication.UnicodeUTF8))
+        self.sysBox.setTitle(QtGui.QApplication.translate("DigitalWindow", "System Parameters", None, QtGui.QApplication.UnicodeUTF8))
+        self.sampleRateLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Sample Rate (sps)", None, QtGui.QApplication.UnicodeUTF8))
+        self.channelModeBox.setTitle(QtGui.QApplication.translate("DigitalWindow", "Channel Model Parameters", None, QtGui.QApplication.UnicodeUTF8))
+        self.snrLabel.setText(QtGui.QApplication.translate("DigitalWindow", "SNR (dB)", None, QtGui.QApplication.UnicodeUTF8))
+        self.freqLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Frequency Offset (Hz)", None, QtGui.QApplication.UnicodeUTF8))
+        self.timeLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Timing Offset", None, QtGui.QApplication.UnicodeUTF8))
+        self.rxBox_2.setTitle(QtGui.QApplication.translate("DigitalWindow", "Received Packet Info", None, QtGui.QApplication.UnicodeUTF8))
+        self.pktsRcvdLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Packets Rcvd.", None, QtGui.QApplication.UnicodeUTF8))
+        self.pktsCorrectLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Packets Correct", None, QtGui.QApplication.UnicodeUTF8))
+        self.perLabel.setText(QtGui.QApplication.translate("DigitalWindow", "PER", None, QtGui.QApplication.UnicodeUTF8))
+        self.pauseButton.setText(QtGui.QApplication.translate("DigitalWindow", "Pause", None, QtGui.QApplication.UnicodeUTF8))
+        self.closeButton.setText(QtGui.QApplication.translate("DigitalWindow", "Close", None, QtGui.QApplication.UnicodeUTF8))
+        self.rxBox.setTitle(QtGui.QApplication.translate("DigitalWindow", "Receiver Parameters", None, QtGui.QApplication.UnicodeUTF8))
+        self.alphaTimeLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Alpha: time", None, QtGui.QApplication.UnicodeUTF8))
+        self.alphaFreqLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Alpha: freq", None, QtGui.QApplication.UnicodeUTF8))
+        self.betaTimeLabel.setText(QtGui.QApplication.translate("DigitalWindow", "Beta: time", None, QtGui.QApplication.UnicodeUTF8))
+        self.menuFile.setTitle(QtGui.QApplication.translate("DigitalWindow", "&File", None, QtGui.QApplication.UnicodeUTF8))
+        self.actionExit.setText(QtGui.QApplication.translate("DigitalWindow", "E&xit", None, QtGui.QApplication.UnicodeUTF8))
+
diff --git a/gnuradio-examples/python/digital/qt_digital_window2.ui b/gnuradio-examples/python/digital/qt_digital_window2.ui
new file mode 100644
index 000000000..dc20ed798
--- /dev/null
+++ b/gnuradio-examples/python/digital/qt_digital_window2.ui
@@ -0,0 +1,637 @@
+<ui version="4.0" >
+ <class>DigitalWindow</class>
+ <widget class="QMainWindow" name="DigitalWindow" >
+  <property name="geometry" >
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>1019</width>
+    <height>754</height>
+   </rect>
+  </property>
+  <property name="windowTitle" >
+   <string>MainWindow</string>
+  </property>
+  <widget class="QWidget" name="centralwidget" >
+   <layout class="QGridLayout" name="gridLayout" >
+    <item row="2" column="0" >
+     <layout class="QVBoxLayout" name="verticalLayout_2" >
+      <item>
+       <widget class="QGroupBox" name="sysBox" >
+        <property name="sizePolicy" >
+         <sizepolicy vsizetype="Fixed" hsizetype="Fixed" >
+          <horstretch>0</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
+        </property>
+        <property name="minimumSize" >
+         <size>
+          <width>240</width>
+          <height>60</height>
+         </size>
+        </property>
+        <property name="maximumSize" >
+         <size>
+          <width>240</width>
+          <height>16777215</height>
+         </size>
+        </property>
+        <property name="title" >
+         <string>System Parameters</string>
+        </property>
+        <widget class="QWidget" name="formLayoutWidget" >
+         <property name="geometry" >
+          <rect>
+           <x>10</x>
+           <y>20</y>
+           <width>211</width>
+           <height>31</height>
+          </rect>
+         </property>
+         <layout class="QFormLayout" name="formLayout" >
+          <property name="sizeConstraint" >
+           <enum>QLayout::SetFixedSize</enum>
+          </property>
+          <property name="verticalSpacing" >
+           <number>20</number>
+          </property>
+          <item row="0" column="1" >
+           <widget class="QLineEdit" name="sampleRateEdit" >
+            <property name="sizePolicy" >
+             <sizepolicy vsizetype="Fixed" hsizetype="Fixed" >
+              <horstretch>0</horstretch>
+              <verstretch>0</verstretch>
+             </sizepolicy>
+            </property>
+            <property name="minimumSize" >
+             <size>
+              <width>60</width>
+              <height>26</height>
+             </size>
+            </property>
+            <property name="maximumSize" >
+             <size>
+              <width>80</width>
+              <height>26</height>
+             </size>
+            </property>
+           </widget>
+          </item>
+          <item row="0" column="0" >
+           <widget class="QLabel" name="sampleRateLabel" >
+            <property name="sizePolicy" >
+             <sizepolicy vsizetype="Fixed" hsizetype="Fixed" >
+              <horstretch>0</horstretch>
+              <verstretch>0</verstretch>
+             </sizepolicy>
+            </property>
+            <property name="minimumSize" >
+             <size>
+              <width>0</width>
+              <height>20</height>
+             </size>
+            </property>
+            <property name="maximumSize" >
+             <size>
+              <width>16777215</width>
+              <height>20</height>
+             </size>
+            </property>
+            <property name="text" >
+             <string>Sample Rate (sps)</string>
+            </property>
+           </widget>
+          </item>
+         </layout>
+        </widget>
+       </widget>
+      </item>
+      <item>
+       <spacer name="verticalSpacer_2" >
+        <property name="orientation" >
+         <enum>Qt::Vertical</enum>
+        </property>
+        <property name="sizeType" >
+         <enum>QSizePolicy::Fixed</enum>
+        </property>
+        <property name="sizeHint" stdset="0" >
+         <size>
+          <width>20</width>
+          <height>60</height>
+         </size>
+        </property>
+       </spacer>
+      </item>
+     </layout>
+    </item>
+    <item row="0" column="0" colspan="6" >
+     <layout class="QVBoxLayout" name="verticalLayout_5" >
+      <item>
+       <widget class="QFrame" name="sinkFrame" >
+        <property name="sizePolicy" >
+         <sizepolicy vsizetype="Expanding" hsizetype="Expanding" >
+          <horstretch>0</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
+        </property>
+        <property name="minimumSize" >
+         <size>
+          <width>500</width>
+          <height>550</height>
+         </size>
+        </property>
+        <property name="frameShape" >
+         <enum>QFrame::StyledPanel</enum>
+        </property>
+        <property name="frameShadow" >
+         <enum>QFrame::Raised</enum>
+        </property>
+        <layout class="QGridLayout" name="gridLayout_2" >
+         <item row="1" column="0" >
+          <layout class="QHBoxLayout" name="sinkLayout" />
+         </item>
+        </layout>
+       </widget>
+      </item>
+     </layout>
+    </item>
+    <item row="2" column="1" >
+     <widget class="QGroupBox" name="channelModeBox" >
+      <property name="sizePolicy" >
+       <sizepolicy vsizetype="Fixed" hsizetype="Fixed" >
+        <horstretch>0</horstretch>
+        <verstretch>0</verstretch>
+       </sizepolicy>
+      </property>
+      <property name="minimumSize" >
+       <size>
+        <width>245</width>
+        <height>130</height>
+       </size>
+      </property>
+      <property name="maximumSize" >
+       <size>
+        <width>245</width>
+        <height>16777215</height>
+       </size>
+      </property>
+      <property name="title" >
+       <string>Channel Model Parameters</string>
+      </property>
+      <widget class="QWidget" name="formLayoutWidget_2" >
+       <property name="geometry" >
+        <rect>
+         <x>10</x>
+         <y>20</y>
+         <width>221</width>
+         <height>98</height>
+        </rect>
+       </property>
+       <layout class="QFormLayout" name="formLayout_2" >
+        <property name="sizeConstraint" >
+         <enum>QLayout::SetFixedSize</enum>
+        </property>
+        <property name="fieldGrowthPolicy" >
+         <enum>QFormLayout::AllNonFixedFieldsGrow</enum>
+        </property>
+        <item row="0" column="0" >
+         <widget class="QLabel" name="snrLabel" >
+          <property name="text" >
+           <string>SNR (dB)</string>
+          </property>
+         </widget>
+        </item>
+        <item row="0" column="1" >
+         <widget class="QLineEdit" name="snrEdit" >
+          <property name="minimumSize" >
+           <size>
+            <width>60</width>
+            <height>0</height>
+           </size>
+          </property>
+          <property name="maximumSize" >
+           <size>
+            <width>80</width>
+            <height>16777215</height>
+           </size>
+          </property>
+         </widget>
+        </item>
+        <item row="1" column="0" >
+         <widget class="QLabel" name="freqLabel" >
+          <property name="text" >
+           <string>Frequency Offset (Hz)</string>
+          </property>
+         </widget>
+        </item>
+        <item row="1" column="1" >
+         <widget class="QLineEdit" name="freqEdit" >
+          <property name="minimumSize" >
+           <size>
+            <width>60</width>
+            <height>0</height>
+           </size>
+          </property>
+          <property name="maximumSize" >
+           <size>
+            <width>80</width>
+            <height>16777215</height>
+           </size>
+          </property>
+         </widget>
+        </item>
+        <item row="2" column="0" >
+         <widget class="QLabel" name="timeLabel" >
+          <property name="text" >
+           <string>Timing Offset</string>
+          </property>
+         </widget>
+        </item>
+        <item row="2" column="1" >
+         <widget class="QLineEdit" name="timeEdit" >
+          <property name="minimumSize" >
+           <size>
+            <width>60</width>
+            <height>0</height>
+           </size>
+          </property>
+          <property name="maximumSize" >
+           <size>
+            <width>80</width>
+            <height>16777215</height>
+           </size>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </widget>
+      <zorder>formLayoutWidget_2</zorder>
+      <zorder>rxBox</zorder>
+     </widget>
+    </item>
+    <item row="2" column="3" >
+     <widget class="QGroupBox" name="rxBox_2" >
+      <property name="sizePolicy" >
+       <sizepolicy vsizetype="Fixed" hsizetype="Fixed" >
+        <horstretch>0</horstretch>
+        <verstretch>0</verstretch>
+       </sizepolicy>
+      </property>
+      <property name="minimumSize" >
+       <size>
+        <width>220</width>
+        <height>125</height>
+       </size>
+      </property>
+      <property name="maximumSize" >
+       <size>
+        <width>265</width>
+        <height>125</height>
+       </size>
+      </property>
+      <property name="title" >
+       <string>Received Packet Info</string>
+      </property>
+      <widget class="QWidget" name="formLayoutWidget_4" >
+       <property name="geometry" >
+        <rect>
+         <x>10</x>
+         <y>20</y>
+         <width>248</width>
+         <height>188</height>
+        </rect>
+       </property>
+       <layout class="QFormLayout" name="formLayout_4" >
+        <property name="sizeConstraint" >
+         <enum>QLayout::SetFixedSize</enum>
+        </property>
+        <property name="fieldGrowthPolicy" >
+         <enum>QFormLayout::AllNonFixedFieldsGrow</enum>
+        </property>
+        <item row="0" column="0" >
+         <widget class="QLabel" name="pktsRcvdLabel" >
+          <property name="text" >
+           <string>Packets Rcvd.</string>
+          </property>
+         </widget>
+        </item>
+        <item row="0" column="1" >
+         <widget class="QLineEdit" name="pktsRcvdEdit" >
+          <property name="minimumSize" >
+           <size>
+            <width>60</width>
+            <height>0</height>
+           </size>
+          </property>
+          <property name="maximumSize" >
+           <size>
+            <width>80</width>
+            <height>16777215</height>
+           </size>
+          </property>
+         </widget>
+        </item>
+        <item row="1" column="0" >
+         <widget class="QLabel" name="pktsCorrectLabel" >
+          <property name="text" >
+           <string>Packets Correct</string>
+          </property>
+         </widget>
+        </item>
+        <item row="1" column="1" >
+         <widget class="QLineEdit" name="pktsCorrectEdit" >
+          <property name="minimumSize" >
+           <size>
+            <width>60</width>
+            <height>0</height>
+           </size>
+          </property>
+          <property name="maximumSize" >
+           <size>
+            <width>80</width>
+            <height>16777215</height>
+           </size>
+          </property>
+         </widget>
+        </item>
+        <item row="2" column="0" >
+         <widget class="QLabel" name="perLabel" >
+          <property name="text" >
+           <string>PER</string>
+          </property>
+         </widget>
+        </item>
+        <item row="2" column="1" >
+         <widget class="QLineEdit" name="perEdit" >
+          <property name="minimumSize" >
+           <size>
+            <width>60</width>
+            <height>0</height>
+           </size>
+          </property>
+          <property name="maximumSize" >
+           <size>
+            <width>80</width>
+            <height>16777215</height>
+           </size>
+          </property>
+         </widget>
+        </item>
+       </layout>
+       <zorder>pktsRcvdLabel</zorder>
+       <zorder>pktsCorrectLabel</zorder>
+       <zorder>perLabel</zorder>
+       <zorder>pktsRcvdEdit</zorder>
+       <zorder>pktsCorrectEdit</zorder>
+       <zorder>perEdit</zorder>
+       <zorder>rxBox</zorder>
+      </widget>
+     </widget>
+    </item>
+    <item row="2" column="4" >
+     <spacer name="horizontalSpacer" >
+      <property name="orientation" >
+       <enum>Qt::Horizontal</enum>
+      </property>
+      <property name="sizeHint" stdset="0" >
+       <size>
+        <width>20</width>
+        <height>20</height>
+       </size>
+      </property>
+     </spacer>
+    </item>
+    <item row="2" column="5" >
+     <layout class="QVBoxLayout" name="verticalLayout" >
+      <item>
+       <widget class="QPushButton" name="pauseButton" >
+        <property name="minimumSize" >
+         <size>
+          <width>80</width>
+          <height>0</height>
+         </size>
+        </property>
+        <property name="maximumSize" >
+         <size>
+          <width>80</width>
+          <height>16777215</height>
+         </size>
+        </property>
+        <property name="text" >
+         <string>Pause</string>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <spacer name="verticalSpacer" >
+        <property name="orientation" >
+         <enum>Qt::Vertical</enum>
+        </property>
+        <property name="sizeType" >
+         <enum>QSizePolicy::Fixed</enum>
+        </property>
+        <property name="sizeHint" stdset="0" >
+         <size>
+          <width>20</width>
+          <height>60</height>
+         </size>
+        </property>
+       </spacer>
+      </item>
+      <item>
+       <widget class="QPushButton" name="closeButton" >
+        <property name="minimumSize" >
+         <size>
+          <width>80</width>
+          <height>0</height>
+         </size>
+        </property>
+        <property name="maximumSize" >
+         <size>
+          <width>80</width>
+          <height>16777215</height>
+         </size>
+        </property>
+        <property name="text" >
+         <string>Close</string>
+        </property>
+       </widget>
+      </item>
+     </layout>
+    </item>
+    <item row="2" column="2" >
+     <widget class="QGroupBox" name="rxBox" >
+      <property name="sizePolicy" >
+       <sizepolicy vsizetype="Fixed" hsizetype="Fixed" >
+        <horstretch>0</horstretch>
+        <verstretch>0</verstretch>
+       </sizepolicy>
+      </property>
+      <property name="minimumSize" >
+       <size>
+        <width>180</width>
+        <height>120</height>
+       </size>
+      </property>
+      <property name="maximumSize" >
+       <size>
+        <width>180</width>
+        <height>16777215</height>
+       </size>
+      </property>
+      <property name="title" >
+       <string>Receiver Parameters</string>
+      </property>
+      <widget class="QWidget" name="formLayoutWidget_3" >
+       <property name="geometry" >
+        <rect>
+         <x>10</x>
+         <y>10</y>
+         <width>161</width>
+         <height>101</height>
+        </rect>
+       </property>
+       <layout class="QFormLayout" name="formLayout_3" >
+        <property name="sizeConstraint" >
+         <enum>QLayout::SetFixedSize</enum>
+        </property>
+        <item row="0" column="0" >
+         <widget class="QLabel" name="alphaTimeLabel" >
+          <property name="text" >
+           <string>Alpha: time</string>
+          </property>
+         </widget>
+        </item>
+        <item row="2" column="0" >
+         <widget class="QLabel" name="alphaFreqLabel" >
+          <property name="text" >
+           <string>Alpha: freq</string>
+          </property>
+         </widget>
+        </item>
+        <item row="0" column="1" >
+         <widget class="QLineEdit" name="alphaTimeEdit" >
+          <property name="minimumSize" >
+           <size>
+            <width>60</width>
+            <height>0</height>
+           </size>
+          </property>
+          <property name="maximumSize" >
+           <size>
+            <width>80</width>
+            <height>16777215</height>
+           </size>
+          </property>
+         </widget>
+        </item>
+        <item row="2" column="1" >
+         <widget class="QLineEdit" name="alphaFreqEdit" >
+          <property name="minimumSize" >
+           <size>
+            <width>60</width>
+            <height>0</height>
+           </size>
+          </property>
+          <property name="maximumSize" >
+           <size>
+            <width>80</width>
+            <height>16777215</height>
+           </size>
+          </property>
+         </widget>
+        </item>
+        <item row="1" column="1" >
+         <widget class="QLineEdit" name="betaTimeEdit" >
+          <property name="maximumSize" >
+           <size>
+            <width>80</width>
+            <height>16777215</height>
+           </size>
+          </property>
+         </widget>
+        </item>
+        <item row="1" column="0" >
+         <widget class="QLabel" name="betaTimeLabel" >
+          <property name="text" >
+           <string>Beta: time</string>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </widget>
+     </widget>
+    </item>
+   </layout>
+   <zorder>channelModeBox</zorder>
+   <zorder></zorder>
+   <zorder>rxBox_2</zorder>
+   <zorder>horizontalSpacer</zorder>
+   <zorder></zorder>
+   <zorder>rxBox</zorder>
+  </widget>
+  <widget class="QMenuBar" name="menubar" >
+   <property name="geometry" >
+    <rect>
+     <x>0</x>
+     <y>0</y>
+     <width>1019</width>
+     <height>24</height>
+    </rect>
+   </property>
+   <widget class="QMenu" name="menuFile" >
+    <property name="title" >
+     <string>&amp;File</string>
+    </property>
+    <addaction name="actionExit" />
+   </widget>
+   <addaction name="menuFile" />
+  </widget>
+  <widget class="QStatusBar" name="statusbar" />
+  <action name="actionExit" >
+   <property name="text" >
+    <string>E&amp;xit</string>
+   </property>
+  </action>
+ </widget>
+ <tabstops>
+  <tabstop>snrEdit</tabstop>
+  <tabstop>freqEdit</tabstop>
+  <tabstop>timeEdit</tabstop>
+ </tabstops>
+ <resources/>
+ <connections>
+  <connection>
+   <sender>closeButton</sender>
+   <signal>clicked()</signal>
+   <receiver>DigitalWindow</receiver>
+   <slot>close()</slot>
+   <hints>
+    <hint type="sourcelabel" >
+     <x>322</x>
+     <y>623</y>
+    </hint>
+    <hint type="destinationlabel" >
+     <x>66</x>
+     <y>561</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>actionExit</sender>
+   <signal>triggered()</signal>
+   <receiver>DigitalWindow</receiver>
+   <slot>close()</slot>
+   <hints>
+    <hint type="sourcelabel" >
+     <x>-1</x>
+     <y>-1</y>
+    </hint>
+    <hint type="destinationlabel" >
+     <x>617</x>
+     <y>327</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
+</ui>