[Commit-gnuradio] r3791 - gnuradio/branches/developers/trondeau/sr_control/gnuradio-examples/python/digital

[trondeau]

Author: trondeau
Date: 2006-10-15 14:31:52 -0600 (Sun, 15 Oct 2006)
New Revision: 3791

Added:
   
gnuradio/branches/developers/trondeau/sr_control/gnuradio-examples/python/digital/pick_bitrate_adv.py
Modified:
   
gnuradio/branches/developers/trondeau/sr_control/gnuradio-examples/python/digital/transmit_path.py
Log:
work in progress

Added: 
gnuradio/branches/developers/trondeau/sr_control/gnuradio-examples/python/digital/pick_bitrate_adv.py
===================================================================
--- 
gnuradio/branches/developers/trondeau/sr_control/gnuradio-examples/python/digital/pick_bitrate_adv.py
                               (rev 0)
+++ 
gnuradio/branches/developers/trondeau/sr_control/gnuradio-examples/python/digital/pick_bitrate_adv.py
       2006-10-15 20:31:52 UTC (rev 3791)
@@ -0,0 +1,147 @@
+#
+# 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.
+# 
+
+_default_bitrate = 500e3
+
+_valid_samples_per_symbol = (2,3,4,5,6,7)
+_max_gr_interp_rate = 20
+_max_gr_decim_rate = 20
+
+def _gen_tx_info(converter_rate):
+    results = []
+    for samples_per_symbol in _valid_samples_per_symbol:
+        for interp in range(16, 512 + 1, 4):
+            for gr_interp in range(1,_max_gr_interp_rate):
+                bitrate = converter_rate / (interp*gr_interp) / 
samples_per_symbol
+                results.append((bitrate, samples_per_symbol, interp, 
gr_interp))
+    results.sort()
+    return results
+
+def _gen_rx_info(converter_rate):
+    results = []
+    for samples_per_symbol in _valid_samples_per_symbol:
+        for decim in range(8, 256 + 1, 2):
+            for gr_decim in range(1,_max_gr_decim_rate):
+                bitrate = converter_rate / (decim*gr_decim) / 
samples_per_symbol
+                results.append((bitrate, samples_per_symbol, decim, gr_decim))
+    results.sort()
+    return results
+    
+def _filter_info(info, samples_per_symbol, xrate):
+    if samples_per_symbol is not None:
+        info = [x for x in info if x[1] == samples_per_symbol]
+    if xrate is not None:
+        info = [x for x in info if x[2] == xrate]
+    return info
+
+def _pick_best(target_bitrate, bits_per_symbol, info):
+    """
+    @returns tuple (bitrate, samples_per_symbol, interp_rate_or_decim_rate)
+    """
+    if len(info) == 0:
+        raise RuntimeError, "info is zero length!"
+
+    if target_bitrate is None:     # return the fastest one
+        return info[-1]
+    
+    # convert bit rate to symbol rate
+    target_symbolrate = target_bitrate / bits_per_symbol
+    
+    # Find the closest matching symbol rate.
+    # In the event of a tie, the one with the lowest samples_per_symbol wins.
+    # (We already sorted them, so the first one is the one we take)
+
+    best = info[0]
+    best_delta = abs(target_symbolrate - best[0])
+    for x in info[1:]:
+        delta = abs(target_symbolrate - x[0])
+        if delta < best_delta:
+            best_delta = delta
+            best = x
+
+    # convert symbol rate back to bit rate
+    return ((best[0] * bits_per_symbol),) + best[1:]
+
+def _pick_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
+                  xrate, converter_rate, gen_info):
+    """
+    @returns tuple (bitrate, samples_per_symbol, interp_rate_or_decim_rate)
+    """
+    if not isinstance(bits_per_symbol, int) or bits_per_symbol < 1:
+        raise ValueError, "bits_per_symbol must be an int >= 1"
+    
+    if samples_per_symbol is not None and xrate is not None:  # completely 
determined
+        return (float(converter_rate) / xrate / samples_per_symbol,
+                samples_per_symbol, xrate)
+
+    if bitrate is None and samples_per_symbol is None and xrate is None:
+        bitrate = _default_bitrate
+
+    # now we have a target bitrate and possibly an xrate or
+    # samples_per_symbol constraint, but not both of them.
+
+    return _pick_best(bitrate, bits_per_symbol,
+                      _filter_info(gen_info(converter_rate), 
samples_per_symbol, xrate))
+    
+# 
---------------------------------------------------------------------------------------
+
+def pick_tx_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
+                    interp_rate, converter_rate=128e6):
+    """
+    Given the 4 input parameters, return at configuration that matches
+
+    @param bitrate: desired bitrate or None
+    @type bitrate: number or None
+    @param bits_per_symbol: E.g., BPSK -> 1, QPSK -> 2, 8-PSK -> 3
+    @type bits_per_symbol: integer >= 1
+    @param samples_per_symbol: samples/baud (aka samples/symbol)
+    @type samples_per_symbol: number or None
+    @param interp_rate: USRP interpolation factor
+    @type interp_rate: integer or None
+    @param converter_rate: converter sample rate in Hz
+    @type converter_rate: number
+
+    @returns tuple (bitrate, samples_per_symbol, interp_rate)
+    """
+    return _pick_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
+                         interp_rate, converter_rate, _gen_tx_info)
+
+
+def pick_rx_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
+                    decim_rate, converter_rate=64e6):
+    """
+    Given the 4 input parameters, return at configuration that matches
+
+    @param bitrate: desired bitrate or None
+    @type bitrate: number or None
+    @param bits_per_symbol: E.g., BPSK -> 1, QPSK -> 2, 8-PSK -> 3
+    @type bits_per_symbol: integer >= 1
+    @param samples_per_symbol: samples/baud (aka samples/symbol)
+    @type samples_per_symbol: number or None
+    @param decim_rate: USRP decimation factor
+    @type decim_rate: integer or None
+    @param converter_rate: converter sample rate in Hz
+    @type converter_rate: number
+
+    @returns tuple (bitrate, samples_per_symbol, decim_rate)
+    """
+    return _pick_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
+                         decim_rate, converter_rate, _gen_rx_info)

Modified: 
gnuradio/branches/developers/trondeau/sr_control/gnuradio-examples/python/digital/transmit_path.py
===================================================================
--- 
gnuradio/branches/developers/trondeau/sr_control/gnuradio-examples/python/digital/transmit_path.py
  2006-10-15 20:03:43 UTC (rev 3790)
+++ 
gnuradio/branches/developers/trondeau/sr_control/gnuradio-examples/python/digital/transmit_path.py
  2006-10-15 20:31:52 UTC (rev 3791)
@@ -27,7 +27,7 @@
 import sys
 
 # from current dir
-from pick_bitrate import pick_tx_bitrate
+from pick_bitrate_adv import pick_tx_bitrate
 
 # /////////////////////////////////////////////////////////////////////////////
 #                              transmit path
@@ -97,8 +97,15 @@
         if self._verbose:
             self._print_verbage()
 
+        # create an interpolating filter for more control and lower symbol 
rates
+        bw = 1
+        sf = 2*self._gr_interp
+        interp_filter_taps = gr.firdes.low_pass(1, sf, bw, bw)
+        #interp_filter_taps = (1,)
+        self.interp = gr.interp_fir_filter_ccf(self._gr_interp, 
interp_filter_taps)
+        
         # Create and setup transmit path flow graph
-        fg.connect(self.packet_transmitter, self.amp, self.u)
+        fg.connect(self.packet_transmitter, self.amp, self.interp, self.u)
         gr.hier_block.__init__(self, fg, None, None)
 
     def _setup_usrp_sink(self):
@@ -111,7 +118,7 @@
         dac_rate = self.u.dac_rate();
 
         # derive values of bitrate, samples_per_symbol, and interp from 
desired info
-        (self._bitrate, self._samples_per_symbol, self._interp) = \
+        (self._bitrate, self._samples_per_symbol, self._interp, 
self._gr_interp) = \
             pick_tx_bitrate(self._bitrate, 
self._modulator_class.bits_per_symbol(),
                             self._samples_per_symbol, self._interp, dac_rate)
         
@@ -214,6 +221,7 @@
         print "bitrate:         %sb/s" % 
(eng_notation.num_to_str(self._bitrate))
         print "samples/symbol:  %3d"   % (self._samples_per_symbol)
         print "interp:          %3d"   % (self._interp)
+        print "gr_interp:       %3d"   % (self._gr_interp)
         print "Tx Frequency:    %s"    % 
(eng_notation.num_to_str(self._tx_freq))