Rework example directories. Gets rid of gnuradio-examples, moves these to more appropriate components.

gnuradio-core and grc now have their own examples directories for files directly related to them.

11 files changed, 2122 insertions, 0 deletions

diff --git a/gnuradio-core/src/examples/pfb/CMakeLists.txt b/gnuradio-core/src/examples/pfb/CMakeLists.txt
new file mode 100644
index 000000000..899c47b90
--- /dev/null
+++ b/gnuradio-core/src/examples/pfb/CMakeLists.txt
@@ -0,0 +1,36 @@
+# Copyright 2011 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(GrPython)
+
+GR_PYTHON_INSTALL(PROGRAMS
+  channelize.py
+  chirp_channelize.py
+  decimate.py
+  fmtest.py
+  interpolate.py
+  resampler_demo.grc
+  resampler.py
+  synth_filter.py
+  synth_to_chan.py
+  reconstruction.py
+  DESTINATION ${GR_PKG_DATA_DIR}/examples/pfb
+  COMPONENT "core_python"
+)
+
diff --git a/gnuradio-core/src/examples/pfb/channelize.py b/gnuradio-core/src/examples/pfb/channelize.py
new file mode 100755
index 000000000..2fcb14a36
--- /dev/null
+++ b/gnuradio-core/src/examples/pfb/channelize.py
@@ -0,0 +1,191 @@
+#!/usr/bin/env python
+#
+# 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.
+# 
+
+from gnuradio import gr, blks2
+import sys, time
+
+try:
+    import scipy
+    from scipy import fftpack
+except ImportError:
+    print "Error: Program requires scipy (see: www.scipy.org)."
+    sys.exit(1)
+
+try:
+    import pylab
+    from pylab import mlab
+except ImportError:
+    print "Error: Program requires matplotlib (see: matplotlib.sourceforge.net)."
+    sys.exit(1)
+
+class pfb_top_block(gr.top_block):
+    def __init__(self):
+        gr.top_block.__init__(self)
+
+        self._N = 2000000        # number of samples to use
+        self._fs = 9000          # initial sampling rate
+        self._M = 9              # Number of channels to channelize
+
+        # Create a set of taps for the PFB channelizer
+        self._taps = gr.firdes.low_pass_2(1, self._fs, 475.50, 50, 
+                                          attenuation_dB=100, window=gr.firdes.WIN_BLACKMAN_hARRIS)
+
+        # Calculate the number of taps per channel for our own information
+        tpc = scipy.ceil(float(len(self._taps)) /  float(self._M))
+        print "Number of taps:     ", len(self._taps)
+        print "Number of channels: ", self._M
+        print "Taps per channel:   ", tpc
+        
+        # Create a set of signals at different frequencies
+        #   freqs lists the frequencies of the signals that get stored 
+        #   in the list "signals", which then get summed together
+        self.signals = list()
+        self.add = gr.add_cc()
+        freqs = [-4070, -3050, -2030, -1010, 10, 1020, 2040, 3060, 4080]
+        for i in xrange(len(freqs)):
+            self.signals.append(gr.sig_source_c(self._fs, gr.GR_SIN_WAVE, freqs[i], 1))
+            self.connect(self.signals[i], (self.add,i))
+
+        self.head = gr.head(gr.sizeof_gr_complex, self._N)
+
+        # Construct the channelizer filter
+        self.pfb = blks2.pfb_channelizer_ccf(self._M, self._taps, 1)
+
+        # Construct a vector sink for the input signal to the channelizer
+        self.snk_i = gr.vector_sink_c()
+
+        # Connect the blocks
+        self.connect(self.add, self.head, self.pfb)
+        self.connect(self.add, self.snk_i)
+
+        # Use this to play with the channel mapping
+        #self.pfb.set_channel_map([5,6,7,8,0,1,2,3,4])
+        
+        # Create a vector sink for each of M output channels of the filter and connect it
+        self.snks = list()
+        for i in xrange(self._M):
+            self.snks.append(gr.vector_sink_c())
+            self.connect((self.pfb, i), self.snks[i])
+                             
+
+def main():
+    tstart = time.time()
+    
+    tb = pfb_top_block()
+    tb.run()
+
+    tend = time.time()
+    print "Run time: %f" % (tend - tstart)
+
+    if 1:
+        fig_in = pylab.figure(1, figsize=(16,9), facecolor="w")
+        fig1 = pylab.figure(2, figsize=(16,9), facecolor="w")
+        fig2 = pylab.figure(3, figsize=(16,9), facecolor="w")
+        
+        Ns = 1000
+        Ne = 10000
+
+        fftlen = 8192
+        winfunc = scipy.blackman
+        fs = tb._fs
+
+        # Plot the input signal on its own figure
+        d = tb.snk_i.data()[Ns:Ne]
+        spin_f = fig_in.add_subplot(2, 1, 1)
+
+        X,freq = mlab.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs,
+                          window = lambda d: d*winfunc(fftlen),
+                          scale_by_freq=True)
+        X_in = 10.0*scipy.log10(abs(X))
+        f_in = scipy.arange(-fs/2.0, fs/2.0, fs/float(X_in.size))
+        pin_f = spin_f.plot(f_in, X_in, "b")
+        spin_f.set_xlim([min(f_in), max(f_in)+1]) 
+        spin_f.set_ylim([-200.0, 50.0]) 
+
+        spin_f.set_title("Input Signal", weight="bold")
+        spin_f.set_xlabel("Frequency (Hz)")
+        spin_f.set_ylabel("Power (dBW)")
+
+
+        Ts = 1.0/fs
+        Tmax = len(d)*Ts
+        
+        t_in = scipy.arange(0, Tmax, Ts)
+        x_in = scipy.array(d)
+        spin_t = fig_in.add_subplot(2, 1, 2)
+        pin_t = spin_t.plot(t_in, x_in.real, "b")
+        pin_t = spin_t.plot(t_in, x_in.imag, "r")
+
+        spin_t.set_xlabel("Time (s)")
+        spin_t.set_ylabel("Amplitude")
+
+        Ncols = int(scipy.floor(scipy.sqrt(tb._M)))
+        Nrows = int(scipy.floor(tb._M / Ncols))
+        if(tb._M % Ncols != 0):
+            Nrows += 1
+
+        # Plot each of the channels outputs. Frequencies on Figure 2 and
+        # time signals on Figure 3
+        fs_o = tb._fs / tb._M
+        Ts_o = 1.0/fs_o
+        Tmax_o = len(d)*Ts_o
+        for i in xrange(len(tb.snks)):
+            # remove issues with the transients at the beginning
+            # also remove some corruption at the end of the stream
+            #    this is a bug, probably due to the corner cases
+            d = tb.snks[i].data()[Ns:Ne]
+
+            sp1_f = fig1.add_subplot(Nrows, Ncols, 1+i)
+            X,freq = mlab.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs_o,
+                              window = lambda d: d*winfunc(fftlen),
+                              scale_by_freq=True)
+            X_o = 10.0*scipy.log10(abs(X))
+            f_o = scipy.arange(-fs_o/2.0, fs_o/2.0, fs_o/float(X_o.size))
+            p2_f = sp1_f.plot(f_o, X_o, "b")
+            sp1_f.set_xlim([min(f_o), max(f_o)+1]) 
+            sp1_f.set_ylim([-200.0, 50.0]) 
+
+            sp1_f.set_title(("Channel %d" % i), weight="bold")
+            sp1_f.set_xlabel("Frequency (Hz)")
+            sp1_f.set_ylabel("Power (dBW)")
+
+            x_o = scipy.array(d)
+            t_o = scipy.arange(0, Tmax_o, Ts_o)
+            sp2_o = fig2.add_subplot(Nrows, Ncols, 1+i)
+            p2_o = sp2_o.plot(t_o, x_o.real, "b")
+            p2_o = sp2_o.plot(t_o, x_o.imag, "r")
+            sp2_o.set_xlim([min(t_o), max(t_o)+1]) 
+            sp2_o.set_ylim([-2, 2]) 
+
+            sp2_o.set_title(("Channel %d" % i), weight="bold")
+            sp2_o.set_xlabel("Time (s)")
+            sp2_o.set_ylabel("Amplitude")
+
+        pylab.show()
+
+
+if __name__ == "__main__":
+    try:
+        main()
+    except KeyboardInterrupt:
+        pass
+    
diff --git a/gnuradio-core/src/examples/pfb/chirp_channelize.py b/gnuradio-core/src/examples/pfb/chirp_channelize.py
new file mode 100755
index 000000000..951255d3b
--- /dev/null
+++ b/gnuradio-core/src/examples/pfb/chirp_channelize.py
@@ -0,0 +1,203 @@
+#!/usr/bin/env python
+#
+# 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.
+# 
+
+from gnuradio import gr, blks2
+import sys, time
+
+try:
+    import scipy
+    from scipy import fftpack
+except ImportError:
+    print "Error: Program requires scipy (see: www.scipy.org)."
+    sys.exit(1)
+
+try:
+    import pylab
+    from pylab import mlab
+except ImportError:
+    print "Error: Program requires matplotlib (see: matplotlib.sourceforge.net)."
+    sys.exit(1)
+
+class pfb_top_block(gr.top_block):
+    def __init__(self):
+        gr.top_block.__init__(self)
+
+        self._N = 200000         # number of samples to use
+        self._fs = 9000          # initial sampling rate
+        self._M = 9              # Number of channels to channelize
+
+        # Create a set of taps for the PFB channelizer
+        self._taps = gr.firdes.low_pass_2(1, self._fs, 500, 20, 
+                                          attenuation_dB=10, window=gr.firdes.WIN_BLACKMAN_hARRIS)
+
+        # Calculate the number of taps per channel for our own information
+        tpc = scipy.ceil(float(len(self._taps)) /  float(self._M))
+        print "Number of taps:     ", len(self._taps)
+        print "Number of channels: ", self._M
+        print "Taps per channel:   ", tpc
+
+        repeated = True
+        if(repeated):
+            self.vco_input = gr.sig_source_f(self._fs, gr.GR_SIN_WAVE, 0.25, 110)
+        else:
+            amp = 100
+            data = scipy.arange(0, amp, amp/float(self._N))
+            self.vco_input = gr.vector_source_f(data, False)
+            
+        # Build a VCO controlled by either the sinusoid or single chirp tone
+        # Then convert this to a complex signal
+        self.vco = gr.vco_f(self._fs, 225, 1)
+        self.f2c = gr.float_to_complex()
+
+        self.head = gr.head(gr.sizeof_gr_complex, self._N)
+
+        # Construct the channelizer filter
+        self.pfb = blks2.pfb_channelizer_ccf(self._M, self._taps)
+
+        # Construct a vector sink for the input signal to the channelizer
+        self.snk_i = gr.vector_sink_c()
+
+        # Connect the blocks
+        self.connect(self.vco_input, self.vco, self.f2c)
+        self.connect(self.f2c, self.head, self.pfb)
+        self.connect(self.f2c, self.snk_i)
+
+        # Create a vector sink for each of M output channels of the filter and connect it
+        self.snks = list()
+        for i in xrange(self._M):
+            self.snks.append(gr.vector_sink_c())
+            self.connect((self.pfb, i), self.snks[i])
+                             
+
+def main():
+    tstart = time.time()
+    
+    tb = pfb_top_block()
+    tb.run()
+
+    tend = time.time()
+    print "Run time: %f" % (tend - tstart)
+
+    if 1:
+        fig_in = pylab.figure(1, figsize=(16,9), facecolor="w")
+        fig1 = pylab.figure(2, figsize=(16,9), facecolor="w")
+        fig2 = pylab.figure(3, figsize=(16,9), facecolor="w")
+        fig3 = pylab.figure(4, figsize=(16,9), facecolor="w")
+        
+        Ns = 650
+        Ne = 20000
+
+        fftlen = 8192
+        winfunc = scipy.blackman
+        fs = tb._fs
+
+        # Plot the input signal on its own figure
+        d = tb.snk_i.data()[Ns:Ne]
+        spin_f = fig_in.add_subplot(2, 1, 1)
+
+        X,freq = mlab.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs,
+                          window = lambda d: d*winfunc(fftlen),
+                          scale_by_freq=True)
+        X_in = 10.0*scipy.log10(abs(fftpack.fftshift(X)))
+        f_in = scipy.arange(-fs/2.0, fs/2.0, fs/float(X_in.size))
+        pin_f = spin_f.plot(f_in, X_in, "b")
+        spin_f.set_xlim([min(f_in), max(f_in)+1]) 
+        spin_f.set_ylim([-200.0, 50.0]) 
+
+        spin_f.set_title("Input Signal", weight="bold")
+        spin_f.set_xlabel("Frequency (Hz)")
+        spin_f.set_ylabel("Power (dBW)")
+
+
+        Ts = 1.0/fs
+        Tmax = len(d)*Ts
+        
+        t_in = scipy.arange(0, Tmax, Ts)
+        x_in = scipy.array(d)
+        spin_t = fig_in.add_subplot(2, 1, 2)
+        pin_t = spin_t.plot(t_in, x_in.real, "b")
+        pin_t = spin_t.plot(t_in, x_in.imag, "r")
+
+        spin_t.set_xlabel("Time (s)")
+        spin_t.set_ylabel("Amplitude")
+
+        Ncols = int(scipy.floor(scipy.sqrt(tb._M)))
+        Nrows = int(scipy.floor(tb._M / Ncols))
+        if(tb._M % Ncols != 0):
+            Nrows += 1
+
+        # Plot each of the channels outputs. Frequencies on Figure 2 and
+        # time signals on Figure 3
+        fs_o = tb._fs / tb._M
+        Ts_o = 1.0/fs_o
+        Tmax_o = len(d)*Ts_o
+        for i in xrange(len(tb.snks)):
+            # remove issues with the transients at the beginning
+            # also remove some corruption at the end of the stream
+            #    this is a bug, probably due to the corner cases
+            d = tb.snks[i].data()[Ns:Ne]
+
+            sp1_f = fig1.add_subplot(Nrows, Ncols, 1+i)
+            X,freq = mlab.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs_o,
+                              window = lambda d: d*winfunc(fftlen),
+                              scale_by_freq=True)
+            X_o = 10.0*scipy.log10(abs(X))
+            f_o = freq
+            p2_f = sp1_f.plot(f_o, X_o, "b")
+            sp1_f.set_xlim([min(f_o), max(f_o)+1]) 
+            sp1_f.set_ylim([-200.0, 50.0]) 
+
+            sp1_f.set_title(("Channel %d" % i), weight="bold")
+            sp1_f.set_xlabel("Frequency (Hz)")
+            sp1_f.set_ylabel("Power (dBW)")
+
+            x_o = scipy.array(d)
+            t_o = scipy.arange(0, Tmax_o, Ts_o)
+            sp2_o = fig2.add_subplot(Nrows, Ncols, 1+i)
+            p2_o = sp2_o.plot(t_o, x_o.real, "b")
+            p2_o = sp2_o.plot(t_o, x_o.imag, "r")
+            sp2_o.set_xlim([min(t_o), max(t_o)+1]) 
+            sp2_o.set_ylim([-2, 2]) 
+
+            sp2_o.set_title(("Channel %d" % i), weight="bold")
+            sp2_o.set_xlabel("Time (s)")
+            sp2_o.set_ylabel("Amplitude")
+
+
+            sp3 = fig3.add_subplot(1,1,1)
+            p3 = sp3.plot(t_o, x_o.real)
+            sp3.set_xlim([min(t_o), max(t_o)+1]) 
+            sp3.set_ylim([-2, 2]) 
+
+        sp3.set_title("All Channels")
+        sp3.set_xlabel("Time (s)")
+        sp3.set_ylabel("Amplitude") 
+
+        pylab.show()
+
+
+if __name__ == "__main__":
+    try:
+        main()
+    except KeyboardInterrupt:
+        pass
+    
diff --git a/gnuradio-core/src/examples/pfb/decimate.py b/gnuradio-core/src/examples/pfb/decimate.py
new file mode 100755
index 000000000..643a2c241
--- /dev/null
+++ b/gnuradio-core/src/examples/pfb/decimate.py
@@ -0,0 +1,178 @@
+#!/usr/bin/env python
+#
+# 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.
+# 
+
+from gnuradio import gr, blks2
+import sys, time
+
+try:
+    import scipy
+    from scipy import fftpack
+except ImportError:
+    print "Error: Program requires scipy (see: www.scipy.org)."
+    sys.exit(1)
+
+try:
+    import pylab
+    from pylab import mlab
+except ImportError:
+    print "Error: Program requires matplotlib (see: matplotlib.sourceforge.net)."
+    sys.exit(1)
+
+class pfb_top_block(gr.top_block):
+    def __init__(self):
+        gr.top_block.__init__(self)
+
+        self._N = 10000000      # number of samples to use
+        self._fs = 10000        # initial sampling rate
+        self._decim = 20        # Decimation rate
+        
+        # Generate the prototype filter taps for the decimators with a 200 Hz bandwidth
+        self._taps = gr.firdes.low_pass_2(1, self._fs, 200, 150,
+                                          attenuation_dB=120, window=gr.firdes.WIN_BLACKMAN_hARRIS)
+
+        # Calculate the number of taps per channel for our own information
+        tpc = scipy.ceil(float(len(self._taps)) /  float(self._decim))
+        print "Number of taps:     ", len(self._taps)
+        print "Number of filters:  ", self._decim
+        print "Taps per channel:   ", tpc
+        
+        # Build the input signal source
+        # We create a list of freqs, and a sine wave is generated and added to the source
+        # for each one of these frequencies.
+        self.signals = list()
+        self.add = gr.add_cc()
+        freqs = [10, 20, 2040]
+        for i in xrange(len(freqs)):
+            self.signals.append(gr.sig_source_c(self._fs, gr.GR_SIN_WAVE, freqs[i], 1))
+            self.connect(self.signals[i], (self.add,i))
+
+        self.head = gr.head(gr.sizeof_gr_complex, self._N)
+        
+        # Construct a PFB decimator filter
+        self.pfb = blks2.pfb_decimator_ccf(self._decim, self._taps, 0)
+
+        # Construct a standard FIR decimating filter
+        self.dec = gr.fir_filter_ccf(self._decim, self._taps)
+
+        self.snk_i = gr.vector_sink_c()
+
+        # Connect the blocks
+        self.connect(self.add, self.head, self.pfb)
+        self.connect(self.add, self.snk_i)
+
+        # Create the sink for the decimated siganl
+        self.snk = gr.vector_sink_c()
+        self.connect(self.pfb, self.snk)
+                             
+
+def main():
+    tb = pfb_top_block()
+
+    tstart = time.time()    
+    tb.run()
+    tend = time.time()
+    print "Run time: %f" % (tend - tstart)
+
+    if 1:
+        fig1 = pylab.figure(1, figsize=(16,9))
+        fig2 = pylab.figure(2, figsize=(16,9))
+        
+        Ns = 10000
+        Ne = 10000
+
+        fftlen = 8192
+        winfunc = scipy.blackman
+        fs = tb._fs
+
+        # Plot the input to the decimator
+
+        d = tb.snk_i.data()[Ns:Ns+Ne]
+        sp1_f = fig1.add_subplot(2, 1, 1)
+
+        X,freq = mlab.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs,
+                          window = lambda d: d*winfunc(fftlen),
+                          scale_by_freq=True)
+        X_in = 10.0*scipy.log10(abs(fftpack.fftshift(X)))
+        f_in = scipy.arange(-fs/2.0, fs/2.0, fs/float(X_in.size))
+        p1_f = sp1_f.plot(f_in, X_in, "b")
+        sp1_f.set_xlim([min(f_in), max(f_in)+1]) 
+        sp1_f.set_ylim([-200.0, 50.0]) 
+
+        sp1_f.set_title("Input Signal", weight="bold")
+        sp1_f.set_xlabel("Frequency (Hz)")
+        sp1_f.set_ylabel("Power (dBW)")
+        
+        Ts = 1.0/fs
+        Tmax = len(d)*Ts
+
+        t_in = scipy.arange(0, Tmax, Ts)
+        x_in = scipy.array(d)
+        sp1_t = fig1.add_subplot(2, 1, 2)
+        p1_t = sp1_t.plot(t_in, x_in.real, "b")
+        p1_t = sp1_t.plot(t_in, x_in.imag, "r")
+        sp1_t.set_ylim([-tb._decim*1.1, tb._decim*1.1])
+
+        sp1_t.set_xlabel("Time (s)")
+        sp1_t.set_ylabel("Amplitude")
+
+        
+        # Plot the output of the decimator
+        fs_o = tb._fs / tb._decim
+
+        sp2_f = fig2.add_subplot(2, 1, 1)
+        d = tb.snk.data()[Ns:Ns+Ne]
+        X,freq = mlab.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs_o,
+                          window = lambda d: d*winfunc(fftlen),
+                          scale_by_freq=True)
+        X_o = 10.0*scipy.log10(abs(fftpack.fftshift(X)))
+        f_o = scipy.arange(-fs_o/2.0, fs_o/2.0, fs_o/float(X_o.size))
+        p2_f = sp2_f.plot(f_o, X_o, "b")
+        sp2_f.set_xlim([min(f_o), max(f_o)+1]) 
+        sp2_f.set_ylim([-200.0, 50.0]) 
+
+        sp2_f.set_title("PFB Decimated Signal", weight="bold")
+        sp2_f.set_xlabel("Frequency (Hz)")
+        sp2_f.set_ylabel("Power (dBW)")
+        
+
+        Ts_o = 1.0/fs_o
+        Tmax_o = len(d)*Ts_o
+
+        x_o = scipy.array(d)
+        t_o = scipy.arange(0, Tmax_o, Ts_o)
+        sp2_t = fig2.add_subplot(2, 1, 2)
+        p2_t = sp2_t.plot(t_o, x_o.real, "b-o")
+        p2_t = sp2_t.plot(t_o, x_o.imag, "r-o")
+        sp2_t.set_ylim([-2.5, 2.5])
+
+        sp2_t.set_xlabel("Time (s)")
+        sp2_t.set_ylabel("Amplitude")
+
+        pylab.show()
+
+
+if __name__ == "__main__":
+    try:
+        main()
+    except KeyboardInterrupt:
+        pass
+    
diff --git a/gnuradio-core/src/examples/pfb/fmtest.py b/gnuradio-core/src/examples/pfb/fmtest.py
new file mode 100755
index 000000000..635ee4e9e
--- /dev/null
+++ b/gnuradio-core/src/examples/pfb/fmtest.py
@@ -0,0 +1,225 @@
+#!/usr/bin/env python
+#
+# 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.
+# 
+
+from gnuradio import gr, blks2
+import sys, math, time
+
+try:
+    import scipy
+    from scipy import fftpack
+except ImportError:
+    print "Error: Program requires scipy (see: www.scipy.org)."
+    sys.exit(1)
+
+try:
+    import pylab
+except ImportError:
+    print "Error: Program requires matplotlib (see: matplotlib.sourceforge.net)."
+    sys.exit(1)
+
+
+class fmtx(gr.hier_block2):
+    def __init__(self, lo_freq, audio_rate, if_rate):
+
+        gr.hier_block2.__init__(self, "build_fm",
+                                gr.io_signature(1, 1, gr.sizeof_float),      # Input signature
+                                gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature
+
+        fmtx = blks2.nbfm_tx (audio_rate, if_rate, max_dev=5e3, tau=75e-6)
+        
+        # Local oscillator
+        lo = gr.sig_source_c (if_rate,        # sample rate
+                              gr.GR_SIN_WAVE, # waveform type
+                              lo_freq,        #frequency
+                              1.0,            # amplitude
+                              0)              # DC Offset
+        mixer = gr.multiply_cc ()
+    
+        self.connect (self, fmtx, (mixer, 0))
+        self.connect (lo, (mixer, 1))
+        self.connect (mixer, self)
+
+class fmtest(gr.top_block):
+    def __init__(self):
+        gr.top_block.__init__(self)
+
+        self._nsamples = 1000000
+        self._audio_rate = 8000
+
+        # Set up N channels with their own baseband and IF frequencies
+        self._N = 5
+        chspacing = 16000
+        freq = [10, 20, 30, 40, 50]
+        f_lo = [0, 1*chspacing, -1*chspacing, 2*chspacing, -2*chspacing]
+
+        self._if_rate = 4*self._N*self._audio_rate
+
+        # Create a signal source and frequency modulate it
+        self.sum = gr.add_cc ()
+        for n in xrange(self._N):
+            sig = gr.sig_source_f(self._audio_rate, gr.GR_SIN_WAVE, freq[n], 0.5)
+            fm = fmtx(f_lo[n], self._audio_rate, self._if_rate)
+            self.connect(sig, fm)
+            self.connect(fm, (self.sum, n))
+
+        self.head = gr.head(gr.sizeof_gr_complex, self._nsamples)
+        self.snk_tx = gr.vector_sink_c()
+        self.channel = blks2.channel_model(0.1)
+
+        self.connect(self.sum, self.head, self.channel, self.snk_tx)
+
+
+        # Design the channlizer
+        self._M = 10
+        bw = chspacing/2.0
+        t_bw = chspacing/10.0
+        self._chan_rate = self._if_rate / self._M
+        self._taps = gr.firdes.low_pass_2(1, self._if_rate, bw, t_bw, 
+                                          attenuation_dB=100,
+                                          window=gr.firdes.WIN_BLACKMAN_hARRIS)
+        tpc = math.ceil(float(len(self._taps)) /  float(self._M))
+
+        print "Number of taps:     ", len(self._taps)
+        print "Number of channels: ", self._M
+        print "Taps per channel:   ", tpc
+        
+        self.pfb = blks2.pfb_channelizer_ccf(self._M, self._taps)
+        
+        self.connect(self.channel, self.pfb)
+        
+        # Create a file sink for each of M output channels of the filter and connect it
+        self.fmdet = list()
+        self.squelch = list()
+        self.snks = list()
+        for i in xrange(self._M):
+            self.fmdet.append(blks2.nbfm_rx(self._audio_rate, self._chan_rate))
+            self.squelch.append(blks2.standard_squelch(self._audio_rate*10))
+            self.snks.append(gr.vector_sink_f())
+            self.connect((self.pfb, i), self.fmdet[i], self.squelch[i], self.snks[i])
+
+    def num_tx_channels(self):
+        return self._N
+
+    def num_rx_channels(self):
+        return self._M
+
+def main():
+
+    fm = fmtest()
+
+    tstart = time.time()
+    fm.run()
+    tend = time.time()
+
+    if 1:
+        fig1 = pylab.figure(1, figsize=(12,10), facecolor="w")
+        fig2 = pylab.figure(2, figsize=(12,10), facecolor="w")
+        fig3 = pylab.figure(3, figsize=(12,10), facecolor="w")
+
+        Ns = 10000
+        Ne = 100000
+
+        fftlen = 8192
+        winfunc = scipy.blackman
+
+        # Plot transmitted signal
+        fs = fm._if_rate
+
+        d = fm.snk_tx.data()[Ns:Ns+Ne]
+        sp1_f = fig1.add_subplot(2, 1, 1)
+
+        X,freq = sp1_f.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs,
+                           window = lambda d: d*winfunc(fftlen),
+                           visible=False)
+        X_in = 10.0*scipy.log10(abs(fftpack.fftshift(X)))
+        f_in = scipy.arange(-fs/2.0, fs/2.0, fs/float(X_in.size))
+        p1_f = sp1_f.plot(f_in, X_in, "b")
+        sp1_f.set_xlim([min(f_in), max(f_in)+1]) 
+        sp1_f.set_ylim([-120.0, 20.0]) 
+
+        sp1_f.set_title("Input Signal", weight="bold")
+        sp1_f.set_xlabel("Frequency (Hz)")
+        sp1_f.set_ylabel("Power (dBW)")
+
+        Ts = 1.0/fs
+        Tmax = len(d)*Ts
+        
+        t_in = scipy.arange(0, Tmax, Ts)
+        x_in = scipy.array(d)
+        sp1_t = fig1.add_subplot(2, 1, 2)
+        p1_t = sp1_t.plot(t_in, x_in.real, "b-o")
+        #p1_t = sp1_t.plot(t_in, x_in.imag, "r-o")
+        sp1_t.set_ylim([-5, 5])
+
+        # Set up the number of rows and columns for plotting the subfigures
+        Ncols = int(scipy.floor(scipy.sqrt(fm.num_rx_channels())))
+        Nrows = int(scipy.floor(fm.num_rx_channels() / Ncols))
+        if(fm.num_rx_channels() % Ncols != 0):
+            Nrows += 1
+
+        # Plot each of the channels outputs. Frequencies on Figure 2 and
+        # time signals on Figure 3
+        fs_o = fm._audio_rate
+        for i in xrange(len(fm.snks)):
+            # remove issues with the transients at the beginning
+            # also remove some corruption at the end of the stream
+            #    this is a bug, probably due to the corner cases
+            d = fm.snks[i].data()[Ns:Ne]
+
+            sp2_f = fig2.add_subplot(Nrows, Ncols, 1+i)
+            X,freq = sp2_f.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs_o,
+                               window = lambda d: d*winfunc(fftlen),
+                               visible=False)
+            #X_o = 10.0*scipy.log10(abs(fftpack.fftshift(X)))
+            X_o = 10.0*scipy.log10(abs(X))
+            #f_o = scipy.arange(-fs_o/2.0, fs_o/2.0, fs_o/float(X_o.size))
+            f_o = scipy.arange(0, fs_o/2.0, fs_o/2.0/float(X_o.size))
+            p2_f = sp2_f.plot(f_o, X_o, "b")
+            sp2_f.set_xlim([min(f_o), max(f_o)+0.1]) 
+            sp2_f.set_ylim([-120.0, 20.0]) 
+            sp2_f.grid(True)
+
+            sp2_f.set_title(("Channel %d" % i), weight="bold")
+            sp2_f.set_xlabel("Frequency (kHz)")
+            sp2_f.set_ylabel("Power (dBW)")
+
+
+            Ts = 1.0/fs_o
+            Tmax = len(d)*Ts
+            t_o = scipy.arange(0, Tmax, Ts)
+
+            x_t = scipy.array(d)
+            sp2_t = fig3.add_subplot(Nrows, Ncols, 1+i)
+            p2_t = sp2_t.plot(t_o, x_t.real, "b")
+            p2_t = sp2_t.plot(t_o, x_t.imag, "r")
+            sp2_t.set_xlim([min(t_o), max(t_o)+1]) 
+            sp2_t.set_ylim([-1, 1]) 
+
+            sp2_t.set_xlabel("Time (s)")
+            sp2_t.set_ylabel("Amplitude")
+
+
+        pylab.show()
+
+
+if __name__ == "__main__":
+    main()
diff --git a/gnuradio-core/src/examples/pfb/interpolate.py b/gnuradio-core/src/examples/pfb/interpolate.py
new file mode 100755
index 000000000..370cf26a7
--- /dev/null
+++ b/gnuradio-core/src/examples/pfb/interpolate.py
@@ -0,0 +1,233 @@
+#!/usr/bin/env python
+#
+# 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.
+# 
+
+from gnuradio import gr, blks2
+import sys, time
+
+try:
+    import scipy
+    from scipy import fftpack
+except ImportError:
+    print "Error: Program requires scipy (see: www.scipy.org)."
+    sys.exit(1)
+
+try:
+    import pylab
+    from pylab import mlab
+except ImportError:
+    print "Error: Program requires matplotlib (see: matplotlib.sourceforge.net)."
+    sys.exit(1)
+
+class pfb_top_block(gr.top_block):
+    def __init__(self):
+        gr.top_block.__init__(self)
+
+        self._N = 100000        # number of samples to use
+        self._fs = 2000         # initial sampling rate
+        self._interp = 5        # Interpolation rate for PFB interpolator
+        self._ainterp = 5.5       # Resampling rate for the PFB arbitrary resampler
+
+        # Frequencies of the signals we construct 
+        freq1 = 100
+        freq2 = 200
+
+        # Create a set of taps for the PFB interpolator
+        # This is based on the post-interpolation sample rate
+        self._taps = gr.firdes.low_pass_2(self._interp, self._interp*self._fs, freq2+50, 50, 
+                                          attenuation_dB=120, window=gr.firdes.WIN_BLACKMAN_hARRIS)
+
+        # Create a set of taps for the PFB arbitrary resampler
+        # The filter size is the number of filters in the filterbank; 32 will give very low side-lobes,
+        # and larger numbers will reduce these even farther
+        # The taps in this filter are based on a sampling rate of the filter size since it acts
+        # internally as an interpolator.
+        flt_size = 32
+        self._taps2 = gr.firdes.low_pass_2(flt_size, flt_size*self._fs, freq2+50, 150, 
+                                           attenuation_dB=120, window=gr.firdes.WIN_BLACKMAN_hARRIS)
+
+        # Calculate the number of taps per channel for our own information
+        tpc = scipy.ceil(float(len(self._taps)) /  float(self._interp))
+        print "Number of taps:     ", len(self._taps)
+        print "Number of filters:  ", self._interp
+        print "Taps per channel:   ", tpc
+
+        # Create a couple of signals at different frequencies
+        self.signal1 = gr.sig_source_c(self._fs, gr.GR_SIN_WAVE, freq1, 0.5)
+        self.signal2 = gr.sig_source_c(self._fs, gr.GR_SIN_WAVE, freq2, 0.5)
+        self.signal = gr.add_cc()
+        
+        self.head = gr.head(gr.sizeof_gr_complex, self._N)
+
+        # Construct the PFB interpolator filter
+        self.pfb = blks2.pfb_interpolator_ccf(self._interp, self._taps)
+
+        # Construct the PFB arbitrary resampler filter
+        self.pfb_ar = blks2.pfb_arb_resampler_ccf(self._ainterp, self._taps2, flt_size)
+        self.snk_i = gr.vector_sink_c()
+
+        #self.pfb_ar.pfb.print_taps()
+        #self.pfb.pfb.print_taps()
+        
+        # Connect the blocks
+        self.connect(self.signal1, self.head, (self.signal,0))
+        self.connect(self.signal2, (self.signal,1))
+        self.connect(self.signal, self.pfb)
+        self.connect(self.signal, self.pfb_ar)
+        self.connect(self.signal, self.snk_i)
+
+        # Create the sink for the interpolated signals
+        self.snk1 = gr.vector_sink_c()
+        self.snk2 = gr.vector_sink_c()
+        self.connect(self.pfb, self.snk1)
+        self.connect(self.pfb_ar, self.snk2)
+                             
+
+def main():
+    tb = pfb_top_block()
+
+    tstart = time.time()
+    tb.run()
+    tend = time.time()
+    print "Run time: %f" % (tend - tstart)
+
+
+    if 1:
+        fig1 = pylab.figure(1, figsize=(12,10), facecolor="w")
+        fig2 = pylab.figure(2, figsize=(12,10), facecolor="w")
+        fig3 = pylab.figure(3, figsize=(12,10), facecolor="w")
+        
+        Ns = 10000
+        Ne = 10000
+
+        fftlen = 8192
+        winfunc = scipy.blackman
+
+        # Plot input signal
+        fs = tb._fs
+
+        d = tb.snk_i.data()[Ns:Ns+Ne]
+        sp1_f = fig1.add_subplot(2, 1, 1)
+
+        X,freq = mlab.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs,
+                          window = lambda d: d*winfunc(fftlen),
+                          scale_by_freq=True)
+        X_in = 10.0*scipy.log10(abs(fftpack.fftshift(X)))
+        f_in = scipy.arange(-fs/2.0, fs/2.0, fs/float(X_in.size))
+        p1_f = sp1_f.plot(f_in, X_in, "b")
+        sp1_f.set_xlim([min(f_in), max(f_in)+1]) 
+        sp1_f.set_ylim([-200.0, 50.0]) 
+
+
+        sp1_f.set_title("Input Signal", weight="bold")
+        sp1_f.set_xlabel("Frequency (Hz)")
+        sp1_f.set_ylabel("Power (dBW)")
+
+        Ts = 1.0/fs
+        Tmax = len(d)*Ts
+        
+        t_in = scipy.arange(0, Tmax, Ts)
+        x_in = scipy.array(d)
+        sp1_t = fig1.add_subplot(2, 1, 2)
+        p1_t = sp1_t.plot(t_in, x_in.real, "b-o")
+        #p1_t = sp1_t.plot(t_in, x_in.imag, "r-o")
+        sp1_t.set_ylim([-2.5, 2.5])
+
+        sp1_t.set_title("Input Signal", weight="bold")
+        sp1_t.set_xlabel("Time (s)")
+        sp1_t.set_ylabel("Amplitude")
+
+
+        # Plot output of PFB interpolator
+        fs_int = tb._fs*tb._interp
+
+        sp2_f = fig2.add_subplot(2, 1, 1)
+        d = tb.snk1.data()[Ns:Ns+(tb._interp*Ne)]
+        X,freq = mlab.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs,
+                          window = lambda d: d*winfunc(fftlen),
+                          scale_by_freq=True)
+        X_o = 10.0*scipy.log10(abs(fftpack.fftshift(X)))
+        f_o = scipy.arange(-fs_int/2.0, fs_int/2.0, fs_int/float(X_o.size))
+        p2_f = sp2_f.plot(f_o, X_o, "b")
+        sp2_f.set_xlim([min(f_o), max(f_o)+1]) 
+        sp2_f.set_ylim([-200.0, 50.0]) 
+
+        sp2_f.set_title("Output Signal from PFB Interpolator", weight="bold")
+        sp2_f.set_xlabel("Frequency (Hz)")
+        sp2_f.set_ylabel("Power (dBW)")
+
+        Ts_int = 1.0/fs_int
+        Tmax = len(d)*Ts_int
+
+        t_o = scipy.arange(0, Tmax, Ts_int)
+        x_o1 = scipy.array(d)
+        sp2_t = fig2.add_subplot(2, 1, 2)
+        p2_t = sp2_t.plot(t_o, x_o1.real, "b-o")
+        #p2_t = sp2_t.plot(t_o, x_o.imag, "r-o")
+        sp2_t.set_ylim([-2.5, 2.5])
+
+        sp2_t.set_title("Output Signal from PFB Interpolator", weight="bold")
+        sp2_t.set_xlabel("Time (s)")
+        sp2_t.set_ylabel("Amplitude")
+
+
+        # Plot output of PFB arbitrary resampler
+        fs_aint = tb._fs * tb._ainterp
+
+        sp3_f = fig3.add_subplot(2, 1, 1)
+        d = tb.snk2.data()[Ns:Ns+(tb._interp*Ne)]
+        X,freq = mlab.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs,
+                          window = lambda d: d*winfunc(fftlen),
+                          scale_by_freq=True)
+        X_o = 10.0*scipy.log10(abs(fftpack.fftshift(X)))
+        f_o = scipy.arange(-fs_aint/2.0, fs_aint/2.0, fs_aint/float(X_o.size))
+        p3_f = sp3_f.plot(f_o, X_o, "b")
+        sp3_f.set_xlim([min(f_o), max(f_o)+1]) 
+        sp3_f.set_ylim([-200.0, 50.0]) 
+
+        sp3_f.set_title("Output Signal from PFB Arbitrary Resampler", weight="bold")
+        sp3_f.set_xlabel("Frequency (Hz)")
+        sp3_f.set_ylabel("Power (dBW)")
+
+        Ts_aint = 1.0/fs_aint
+        Tmax = len(d)*Ts_aint
+
+        t_o = scipy.arange(0, Tmax, Ts_aint)
+        x_o2 = scipy.array(d)
+        sp3_f = fig3.add_subplot(2, 1, 2)
+        p3_f = sp3_f.plot(t_o, x_o2.real, "b-o")
+        p3_f = sp3_f.plot(t_o, x_o1.real, "m-o")
+        #p3_f = sp3_f.plot(t_o, x_o2.imag, "r-o")
+        sp3_f.set_ylim([-2.5, 2.5])
+        
+        sp3_f.set_title("Output Signal from PFB Arbitrary Resampler", weight="bold")
+        sp3_f.set_xlabel("Time (s)")
+        sp3_f.set_ylabel("Amplitude")
+
+        pylab.show()
+
+
+if __name__ == "__main__":
+    try:
+        main()
+    except KeyboardInterrupt:
+        pass
+    
diff --git a/gnuradio-core/src/examples/pfb/reconstruction.py b/gnuradio-core/src/examples/pfb/reconstruction.py
new file mode 100755
index 000000000..c7909f7a5
--- /dev/null
+++ b/gnuradio-core/src/examples/pfb/reconstruction.py
@@ -0,0 +1,131 @@
+#!/usr/bin/env python
+
+import scipy, math, pylab
+from scipy import fftpack
+from gnuradio import gr, digital, blks2
+
+fftlen = 8192
+
+def main():
+    N = 10000
+    fs = 2000.0
+    Ts = 1.0/fs
+    t = scipy.arange(0, N*Ts, Ts)
+
+    # When playing with the number of channels, be careful about the filter
+    # specs and the channel map of the synthesizer set below.
+    nchans = 10
+
+    # Build the filter(s)
+    bw = 1000
+    tb = 400
+    proto_taps = gr.firdes.low_pass_2(1, nchans*fs, bw, tb, 80,
+                                      gr.firdes.WIN_BLACKMAN_hARRIS)
+    print "Filter length: ", len(proto_taps)
+
+
+    # Create a modulated signal
+    npwr = 0.01
+    data = scipy.random.randint(0, 256, N)
+    rrc_taps = gr.firdes.root_raised_cosine(1, 2, 1, 0.35, 41)
+
+    src = gr.vector_source_b(data.astype(scipy.uint8).tolist(), False)
+    mod = digital.bpsk_mod(samples_per_symbol=2)
+    chan = gr.channel_model(npwr)
+    rrc = gr.fft_filter_ccc(1, rrc_taps)
+
+    # Split it up into pieces
+    channelizer = blks2.pfb_channelizer_ccf(nchans, proto_taps, 2)
+    
+    # Put the pieces back together again
+    syn_taps = [nchans*t for t in proto_taps]
+    synthesizer = gr.pfb_synthesizer_ccf(nchans, syn_taps, True)
+    src_snk = gr.vector_sink_c()
+    snk = gr.vector_sink_c()
+
+    # Remap the location of the channels
+    # Can be done in synth or channelizer (watch out for rotattions in
+    # the channelizer)
+    synthesizer.set_channel_map([ 0,  1,  2,  3,  4,
+                                 15, 16, 17, 18, 19])
+    
+    tb = gr.top_block()
+    tb.connect(src, mod, chan, rrc, channelizer)
+    tb.connect(rrc, src_snk)
+
+    vsnk = []
+    for i in xrange(nchans):
+        tb.connect((channelizer,i), (synthesizer, i))
+
+        vsnk.append(gr.vector_sink_c())
+        tb.connect((channelizer,i), vsnk[i])
+        
+    tb.connect(synthesizer, snk)
+    tb.run()
+    
+    sin  = scipy.array(src_snk.data()[1000:])
+    sout = scipy.array(snk.data()[1000:])
+
+    
+    # Plot original signal
+    fs_in = nchans*fs
+    f1 = pylab.figure(1, figsize=(16,12), facecolor='w')
+    s11 = f1.add_subplot(2,2,1)
+    s11.psd(sin, NFFT=fftlen, Fs=fs_in)
+    s11.set_title("PSD of Original Signal")
+    s11.set_ylim([-200, -20])
+
+    s12 = f1.add_subplot(2,2,2)
+    s12.plot(sin.real[1000:1500], "o-b")
+    s12.plot(sin.imag[1000:1500], "o-r")
+    s12.set_title("Original Signal in Time")
+
+    start = 1
+    skip  = 4
+    s13 = f1.add_subplot(2,2,3)
+    s13.plot(sin.real[start::skip], sin.imag[start::skip], "o")
+    s13.set_title("Constellation")
+    s13.set_xlim([-2, 2])
+    s13.set_ylim([-2, 2])
+    
+    # Plot channels
+    nrows = int(scipy.sqrt(nchans))
+    ncols = int(scipy.ceil(float(nchans)/float(nrows)))
+
+    f2 = pylab.figure(2, figsize=(16,12), facecolor='w')
+    for n in xrange(nchans):
+        s = f2.add_subplot(nrows, ncols, n+1)
+        s.psd(vsnk[n].data(), NFFT=fftlen, Fs=fs_in)
+        s.set_title("Channel {0}".format(n))
+        s.set_ylim([-200, -20])
+
+    # Plot reconstructed signal
+    fs_out = 2*nchans*fs
+    f3 = pylab.figure(3, figsize=(16,12), facecolor='w')
+    s31 = f3.add_subplot(2,2,1)
+    s31.psd(sout, NFFT=fftlen, Fs=fs_out)
+    s31.set_title("PSD of Reconstructed Signal")
+    s31.set_ylim([-200, -20])
+
+    s32 = f3.add_subplot(2,2,2)
+    s32.plot(sout.real[1000:1500], "o-b")
+    s32.plot(sout.imag[1000:1500], "o-r")
+    s32.set_title("Reconstructed Signal in Time")
+
+    start = 2
+    skip  = 4
+    s33 = f3.add_subplot(2,2,3)
+    s33.plot(sout.real[start::skip], sout.imag[start::skip], "o")
+    s33.set_title("Constellation")
+    s33.set_xlim([-2, 2])
+    s33.set_ylim([-2, 2])
+
+    pylab.show()
+
+    
+if __name__ == "__main__":
+    try:
+        main()
+    except KeyboardInterrupt:
+        pass
+
diff --git a/gnuradio-core/src/examples/pfb/resampler.py b/gnuradio-core/src/examples/pfb/resampler.py
new file mode 100755
index 000000000..7b296ca71
--- /dev/null
+++ b/gnuradio-core/src/examples/pfb/resampler.py
@@ -0,0 +1,127 @@
+#!/usr/bin/env python
+#
+# 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.
+# 
+
+from gnuradio import gr, blks2
+import sys
+
+try:
+    import scipy
+except ImportError:
+    print "Error: Program requires scipy (see: www.scipy.org)."
+    sys.exit(1)
+
+try:
+    import pylab
+except ImportError:
+    print "Error: Program requires matplotlib (see: matplotlib.sourceforge.net)."
+    sys.exit(1)
+
+class mytb(gr.top_block):
+    def __init__(self, fs_in, fs_out, fc, N=10000):
+        gr.top_block.__init__(self)
+        
+        rerate = float(fs_out) / float(fs_in)
+        print "Resampling from %f to %f by %f " %(fs_in, fs_out, rerate)
+
+        # Creating our own taps
+        taps = gr.firdes.low_pass_2(32, 32, 0.25, 0.1, 80)
+
+        self.src = gr.sig_source_c(fs_in, gr.GR_SIN_WAVE, fc, 1)
+        #self.src = gr.noise_source_c(gr.GR_GAUSSIAN, 1)
+        self.head = gr.head(gr.sizeof_gr_complex, N)
+
+        # A resampler with our taps
+        self.resamp_0 = blks2.pfb_arb_resampler_ccf(rerate, taps,
+                                                    flt_size=32)
+
+        # A resampler that just needs a resampling rate.
+        # Filter is created for us and designed to cover
+        # entire bandwidth of the input signal.
+        # An optional atten=XX rate can be used here to 
+        # specify the out-of-band rejection (default=80).
+        self.resamp_1 = blks2.pfb_arb_resampler_ccf(rerate)
+
+        self.snk_in = gr.vector_sink_c()
+        self.snk_0 = gr.vector_sink_c()
+        self.snk_1 = gr.vector_sink_c()
+
+        self.connect(self.src, self.head, self.snk_in)
+        self.connect(self.head, self.resamp_0, self.snk_0)
+        self.connect(self.head, self.resamp_1, self.snk_1)
+
+def main():
+    fs_in = 8000
+    fs_out = 20000
+    fc = 1000
+    N = 10000
+
+    tb = mytb(fs_in, fs_out, fc, N)
+    tb.run()
+
+
+    # Plot PSD of signals
+    nfftsize = 2048
+    fig1 = pylab.figure(1, figsize=(10,10), facecolor="w")
+    sp1 = fig1.add_subplot(2,1,1)
+    sp1.psd(tb.snk_in.data(), NFFT=nfftsize,
+            noverlap=nfftsize/4, Fs = fs_in)
+    sp1.set_title(("Input Signal at f_s=%.2f kHz" % (fs_in/1000.0)))
+    sp1.set_xlim([-fs_in/2, fs_in/2])
+
+    sp2 = fig1.add_subplot(2,1,2)
+    sp2.psd(tb.snk_0.data(), NFFT=nfftsize,
+            noverlap=nfftsize/4, Fs = fs_out,
+            label="With our filter")
+    sp2.psd(tb.snk_1.data(), NFFT=nfftsize,
+            noverlap=nfftsize/4, Fs = fs_out,
+            label="With auto-generated filter")
+    sp2.set_title(("Output Signals at f_s=%.2f kHz" % (fs_out/1000.0)))
+    sp2.set_xlim([-fs_out/2, fs_out/2])
+    sp2.legend()
+
+    # Plot signals in time
+    Ts_in = 1.0/fs_in
+    Ts_out = 1.0/fs_out
+    t_in = scipy.arange(0, len(tb.snk_in.data())*Ts_in, Ts_in)
+    t_out = scipy.arange(0, len(tb.snk_0.data())*Ts_out, Ts_out)
+
+    fig2 = pylab.figure(2, figsize=(10,10), facecolor="w")
+    sp21 = fig2.add_subplot(2,1,1)
+    sp21.plot(t_in, tb.snk_in.data())
+    sp21.set_title(("Input Signal at f_s=%.2f kHz" % (fs_in/1000.0)))
+    sp21.set_xlim([t_in[100], t_in[200]])
+
+    sp22 = fig2.add_subplot(2,1,2)
+    sp22.plot(t_out, tb.snk_0.data(),
+              label="With our filter")
+    sp22.plot(t_out, tb.snk_1.data(),
+              label="With auto-generated filter")
+    sp22.set_title(("Output Signals at f_s=%.2f kHz" % (fs_out/1000.0)))
+    r = float(fs_out)/float(fs_in)
+    sp22.set_xlim([t_out[r * 100], t_out[r * 200]])
+    sp22.legend()
+
+    pylab.show()
+
+if __name__ == "__main__":
+    main()
+
diff --git a/gnuradio-core/src/examples/pfb/resampler_demo.grc b/gnuradio-core/src/examples/pfb/resampler_demo.grc
new file mode 100644
index 000000000..468636a5c
--- /dev/null
+++ b/gnuradio-core/src/examples/pfb/resampler_demo.grc
@@ -0,0 +1,598 @@
+<?xml version='1.0' encoding='ASCII'?>
+<flow_graph>
+  <timestamp>Sun Aug 23 11:39:47 2009</timestamp>
+  <block>
+    <key>options</key>
+    <param>
+      <key>id</key>
+      <value>resampler_demo</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</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>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>(11, 59)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>rs_taps</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>firdes.low_pass(nphases, nphases, frac_bw, 0.5-frac_bw)</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(273, 154)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_add_const_vxx</key>
+    <param>
+      <key>id</key>
+      <value>adder</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>float</value>
+    </param>
+    <param>
+      <key>const</key>
+      <value>-1.0</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(227, 303)</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>samp_rate</value>
+    </param>
+    <param>
+      <key>vlen</key>
+      <value>1</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(227, 493)</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>complex</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Original Spectrum</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>30</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, 3</value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(409, 289)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</value>
+    </param>
+  </block>
+  <block>
+    <key>wxgui_fftsink2</key>
+    <param>
+      <key>id</key>
+      <value>resamp_fft</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>type</key>
+      <value>complex</value>
+    </param>
+    <param>
+      <key>title</key>
+      <value>Resampled Spectrum</value>
+    </param>
+    <param>
+      <key>samp_rate</key>
+      <value>new_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>30</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>True</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, 1, 3</value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(640, 256)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>180</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>samp_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>2.0</value>
+    </param>
+    <param>
+      <key>offset</key>
+      <value>0</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(21, 271)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>gr_frequency_modulator_fc</key>
+    <param>
+      <key>id</key>
+      <value>fm_mod</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>sensitivity</key>
+      <value>math.pi</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(411, 493)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>blks2_pfb_arb_resampler_ccf</key>
+    <param>
+      <key>id</key>
+      <value>resampler</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>rate</key>
+      <value>float(new_rate)/samp_rate</value>
+    </param>
+    <param>
+      <key>taps</key>
+      <value>rs_taps</value>
+    </param>
+    <param>
+      <key>size</key>
+      <value>nphases</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(641, 477)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable</key>
+    <param>
+      <key>id</key>
+      <value>nphases</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>32</value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(185, 153)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_static_text</key>
+    <param>
+      <key>id</key>
+      <value>samp_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Sample Rate</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>44100</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>formatter</key>
+      <value>None</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>0, 0, 1, 1</value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(179, 14)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_static_text</key>
+    <param>
+      <key>id</key>
+      <value>new_rate</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Resampled Rate</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>48000</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>formatter</key>
+      <value>None</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>0, 1, 1, 1</value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(328, 15)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <block>
+    <key>variable_static_text</key>
+    <param>
+      <key>id</key>
+      <value>frac_bw</value>
+    </param>
+    <param>
+      <key>_enabled</key>
+      <value>True</value>
+    </param>
+    <param>
+      <key>label</key>
+      <value>Fractional Bandwidth</value>
+    </param>
+    <param>
+      <key>value</key>
+      <value>0.45</value>
+    </param>
+    <param>
+      <key>converver</key>
+      <value>float_converter</value>
+    </param>
+    <param>
+      <key>formatter</key>
+      <value>lambda x: "%0.2f"%x</value>
+    </param>
+    <param>
+      <key>grid_pos</key>
+      <value>0,2,1,1</value>
+    </param>
+    <param>
+      <key>notebook</key>
+      <value></value>
+    </param>
+    <param>
+      <key>_coordinate</key>
+      <value>(473, 14)</value>
+    </param>
+    <param>
+      <key>_rotation</key>
+      <value>0</value>
+    </param>
+  </block>
+  <connection>
+    <source_block_id>tri_source</source_block_id>
+    <sink_block_id>adder</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>adder</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>resampler</source_block_id>
+    <sink_block_id>resamp_fft</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>fm_mod</source_block_id>
+    <sink_block_id>resampler</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+  <connection>
+    <source_block_id>fm_mod</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>throttle</source_block_id>
+    <sink_block_id>fm_mod</sink_block_id>
+    <source_key>0</source_key>
+    <sink_key>0</sink_key>
+  </connection>
+</flow_graph>
diff --git a/gnuradio-core/src/examples/pfb/synth_filter.py b/gnuradio-core/src/examples/pfb/synth_filter.py
new file mode 100755
index 000000000..a91edfebf
--- /dev/null
+++ b/gnuradio-core/src/examples/pfb/synth_filter.py
@@ -0,0 +1,83 @@
+#!/usr/bin/env python
+#
+# Copyright 2010 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.
+# 
+
+from gnuradio import gr, blks2
+import sys 
+
+try:
+    import scipy
+except ImportError:
+    print "Error: Program requires scipy (see: www.scipy.org)."
+    sys.exit(1)
+
+try:
+    import pylab
+except ImportError:
+    print "Error: Program requires matplotlib (see: matplotlib.sourceforge.net)."
+    sys.exit(1)
+
+def main():
+    N = 1000000
+    fs = 8000
+
+    freqs = [100, 200, 300, 400, 500]
+    nchans = 7
+
+    sigs = list()
+    for fi in freqs:
+        s = gr.sig_source_c(fs, gr.GR_SIN_WAVE, fi, 1)
+        sigs.append(s)
+
+    taps = gr.firdes.low_pass_2(len(freqs), fs, fs/float(nchans)/2, 100, 100)
+    print "Num. Taps = %d (taps per filter = %d)" % (len(taps), 
+                                                     len(taps)/nchans)
+    filtbank = gr.pfb_synthesizer_ccf(nchans, taps)
+
+    head = gr.head(gr.sizeof_gr_complex, N)
+    snk = gr.vector_sink_c()
+
+    tb = gr.top_block()
+    tb.connect(filtbank, head, snk)
+
+    for i,si in enumerate(sigs):
+        tb.connect(si, (filtbank, i))
+    
+    tb.run()
+
+    if 1:
+        f1 = pylab.figure(1)
+        s1 = f1.add_subplot(1,1,1)
+        s1.plot(snk.data()[1000:])
+        
+        fftlen = 2048
+        f2 = pylab.figure(2)
+        s2 = f2.add_subplot(1,1,1)
+        winfunc = scipy.blackman
+        s2.psd(snk.data()[10000:], NFFT=fftlen,
+               Fs = nchans*fs,
+               noverlap=fftlen/4,
+               window = lambda d: d*winfunc(fftlen))
+
+        pylab.show()
+
+if __name__ == "__main__":
+    main()
diff --git a/gnuradio-core/src/examples/pfb/synth_to_chan.py b/gnuradio-core/src/examples/pfb/synth_to_chan.py
new file mode 100755
index 000000000..c6c80b2f8
--- /dev/null
+++ b/gnuradio-core/src/examples/pfb/synth_to_chan.py
@@ -0,0 +1,117 @@
+#!/usr/bin/env python
+#
+# Copyright 2010 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.
+# 
+
+from gnuradio import gr, blks2
+import sys 
+
+try:
+    import scipy
+except ImportError:
+    print "Error: Program requires scipy (see: www.scipy.org)."
+    sys.exit(1)
+
+try:
+    import pylab
+except ImportError:
+    print "Error: Program requires matplotlib (see: matplotlib.sourceforge.net)."
+    sys.exit(1)
+
+def main():
+    N = 1000000
+    fs = 8000
+
+    freqs = [100, 200, 300, 400, 500]
+    nchans = 7
+
+    sigs = list()
+    fmtx = list()
+    for fi in freqs:
+        s = gr.sig_source_f(fs, gr.GR_SIN_WAVE, fi, 1)
+        fm = blks2.nbfm_tx (fs, 4*fs, max_dev=10000, tau=75e-6)
+        sigs.append(s)
+        fmtx.append(fm)
+
+    syntaps = gr.firdes.low_pass_2(len(freqs), fs, fs/float(nchans)/2, 100, 100)
+    print "Synthesis Num. Taps = %d (taps per filter = %d)" % (len(syntaps), 
+                                                               len(syntaps)/nchans)
+    chtaps = gr.firdes.low_pass_2(len(freqs), fs, fs/float(nchans)/2, 100, 100)
+    print "Channelizer Num. Taps = %d (taps per filter = %d)" % (len(chtaps), 
+                                                                 len(chtaps)/nchans)
+    filtbank = gr.pfb_synthesizer_ccf(nchans, syntaps)
+    channelizer = blks2.pfb_channelizer_ccf(nchans, chtaps)
+
+    noise_level = 0.01
+    head = gr.head(gr.sizeof_gr_complex, N)
+    noise = gr.noise_source_c(gr.GR_GAUSSIAN, noise_level)
+    addnoise = gr.add_cc()
+    snk_synth = gr.vector_sink_c()
+
+    tb = gr.top_block()
+
+    tb.connect(noise, (addnoise,0))
+    tb.connect(filtbank, head, (addnoise, 1))
+    tb.connect(addnoise, channelizer)
+    tb.connect(addnoise, snk_synth)
+
+    snk = list()
+    for i,si in enumerate(sigs):
+        tb.connect(si, fmtx[i], (filtbank, i))
+
+    for i in xrange(nchans):
+        snk.append(gr.vector_sink_c())
+        tb.connect((channelizer, i), snk[i])
+    
+    tb.run()
+
+    if 1:
+        channel = 1
+        data = snk[channel].data()[1000:]
+
+        f1 = pylab.figure(1)
+        s1 = f1.add_subplot(1,1,1)
+        s1.plot(data[10000:10200] )
+        s1.set_title(("Output Signal from Channel %d" % channel))
+        
+        fftlen = 2048
+        winfunc = scipy.blackman
+        #winfunc = scipy.hamming
+
+        f2 = pylab.figure(2)
+        s2 = f2.add_subplot(1,1,1)
+        s2.psd(data, NFFT=fftlen,
+               Fs = nchans*fs,
+               noverlap=fftlen/4,
+               window = lambda d: d*winfunc(fftlen))
+        s2.set_title(("Output PSD from Channel %d" % channel))
+
+        f3 = pylab.figure(3)
+        s3 = f3.add_subplot(1,1,1)
+        s3.psd(snk_synth.data()[1000:], NFFT=fftlen,
+               Fs = nchans*fs,
+               noverlap=fftlen/4,
+               window = lambda d: d*winfunc(fftlen))
+        s3.set_title("Output of Synthesis Filter")
+
+        pylab.show()
+
+if __name__ == "__main__":
+    main()