Merged r4518:5130 from developer branch n4hy/ofdm into trunk, passes distcheck.

Adds incomplete OFDM implementation, further work to be completed in the
features/ofdm branch.


git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@5131 221aa14e-8319-0410-a670-987f0aec2ac5

1 files changed, 104 insertions, 0 deletions

diff --git a/gnuradio-examples/python/ofdm/transmit_path.py b/gnuradio-examples/python/ofdm/transmit_path.py
new file mode 100644
index 000000000..308ec0851
--- /dev/null
+++ b/gnuradio-examples/python/ofdm/transmit_path.py
@@ -0,0 +1,104 @@
+#
+# Copyright 2005,2006 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 2, 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, gru, blks
+from gnuradio import usrp
+from gnuradio import eng_notation
+
+import copy
+import sys
+
+# from current dir
+import ofdm
+
+# /////////////////////////////////////////////////////////////////////////////
+#                              transmit path
+# /////////////////////////////////////////////////////////////////////////////
+
+class transmit_path(gr.hier_block): 
+    def __init__(self, fg, options):
+        '''
+        See below for what options should hold
+        '''
+
+        options = copy.copy(options)    # make a copy so we can destructively modify
+
+        self._verbose      = options.verbose
+        self._tx_amplitude = options.tx_amplitude    # digital amplitude sent to USRP
+
+        self.ofdm_mod = ofdm.ofdm_mod(fg, options)
+        self.packet_transmitter = \
+            blks.mod_ofdm_pkts(fg,
+                               self.ofdm_mod,
+                               access_code=None,
+                               msgq_limit=4,
+                               pad_for_usrp=True)
+
+        self.amp = gr.multiply_const_cc(1)
+        self.set_tx_amplitude(self._tx_amplitude)
+
+        # Display some information about the setup
+        if self._verbose:
+            self._print_verbage()
+
+        # Create and setup transmit path flow graph
+        fg.connect(self.packet_transmitter, self.amp)
+        gr.hier_block.__init__(self, fg, None, self.amp)
+
+    def set_tx_amplitude(self, ampl):
+        """
+        Sets the transmit amplitude sent to the USRP
+        @param: ampl 0 <= ampl < 32768.  Try 8000
+        """
+        self._tx_amplitude = max(0.0, min(ampl, 32767.0))
+        self.amp.set_k(self._tx_amplitude)
+        
+    def send_pkt(self, payload='', eof=False):
+        """
+        Calls the transmitter method to send a packet
+        """
+        return self.packet_transmitter.send_pkt(payload, eof)
+        
+    def bitrate(self):
+        return self._bitrate
+
+    def samples_per_symbol(self):
+        return self._samples_per_symbol
+
+    def add_options(normal, expert):
+        """
+        Adds transmitter-specific options to the Options Parser
+        """
+        normal.add_option("", "--tx-amplitude", type="eng_float", default=12000, metavar="AMPL",
+                          help="set transmitter digital amplitude: 0 <= AMPL < 32768 [default=%default]")
+        normal.add_option("-v", "--verbose", action="store_true", default=False)
+        expert.add_option("", "--log", action="store_true", default=False,
+                          help="Log all parts of flow graph to file (CAUTION: lots of data)")
+
+    # Make a static method to call before instantiation
+    add_options = staticmethod(add_options)
+
+    def _print_verbage(self):
+        """
+        Prints information about the transmit path
+        """
+        print "Tx amplitude     %s"    % (self._tx_amplitude)
+