From b845770e33b584a88150dc97b45c7b0807791693 Mon Sep 17 00:00:00 2001
From: Tom Rondeau
Date: Wed, 10 Feb 2010 16:12:32 -0800
Subject: Working on pick_bitrate.

---
 gnuradio-examples/python/digital/pick_bitrate2.py | 92 +++++++++++++++++------
 1 file changed, 67 insertions(+), 25 deletions(-)

(limited to 'gnuradio-examples')

diff --git a/gnuradio-examples/python/digital/pick_bitrate2.py b/gnuradio-examples/python/digital/pick_bitrate2.py
index c0188dc3c..b678f7254 100644
--- a/gnuradio-examples/python/digital/pick_bitrate2.py
+++ b/gnuradio-examples/python/digital/pick_bitrate2.py
@@ -1,39 +1,74 @@
+#
+# 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 eng_notation
 
-def pick_rx_bitrate(bitrate, bits_per_symbol,
-                    converter_rate, possible_decims):
+_default_bitrate = 500e3
+
+def _pick_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
+                  xrate, converter_rate, xrates, gen_info):
+    """
+    @returns tuple (bitrate, samples_per_symbol, interp_rate_or_decim_rate)
     """
-    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 converter_rate: converter sample rate in Hz
-    @type converter_rate: number
-    @param possible_decims: a list of possible rates
-    @type possible_decims: a list of integers
+    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)
 
-    @returns tuple (bitrate, samples_per_symbol, decim_rate)
-    """
+    # If no parameters are give, use the default bit rate
+    if bitrate is None and samples_per_symbol is None and xrate is None:
+        bitrate = _default_bitrate
 
-    rates = list(possible_decims)
-    rates.sort()
+    # If only bitrate is specified, return max xrate and appropriate
+    # samples per symbol to reach bit rate
+    if samples_per_symbol is None and xrate is None:
+        xrates.sort()
+        for i in xrange(len(xrates)):
+            if((converter_rate / float(bits_per_symbol) / xrates[i]) >= 2*bitrate):
+                decim = xrates[i]
+            else:
+                break
+            
+        sps = converter_rate / float(bits_per_symbol) / decim / bitrate
+        br = converter_rate / float(bits_per_symbol) / decim / sps
+
+        return (br, sps, int(decim))
 
-    for i in xrange(len(rates)):
-        if((converter_rate / float(bits_per_symbol) / rates[i]) >= 2*bitrate):
-            decim = rates[i]
-        else:
-            break
 
-    sps = converter_rate / float(bits_per_symbol) / decim / bitrate
-    br = converter_rate / float(bits_per_symbol) / decim / sps
+    # now we have a target bitrate and possibly an xrate or
+    # samples_per_symbol constraint, but not both of them.
+    ret = _pick_best(bitrate, bits_per_symbol,
+                      _filter_info(gen_info(converter_rate, xrates),
+                                   samples_per_symbol, xrate))
 
-    return (br, sps, int(decim))
+    print "Actual Bitrate:", eng_notation.num_to_str(ret[0])
+    return ret
 
 
-def pick_tx_bitrate(bitrate, bits_per_symbol,
-                    converter_rate, possible_interps):
+
+def pick_tx_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
+                    interp_rate, converter_rate, possible_interps):
     """
     Given the 4 input parameters, return at configuration that matches
 
@@ -41,6 +76,10 @@ def pick_tx_bitrate(bitrate, bits_per_symbol,
     @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
     @param possible_interps: a list of possible rates
@@ -49,6 +88,9 @@ def pick_tx_bitrate(bitrate, bits_per_symbol,
     @returns tuple (bitrate, samples_per_symbol, interp_rate)
     """
 
+    return _pick_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
+                         interp_rate, converter_rate, possible_interps, _gen_tx_info)
+
     rates = list(possible_interps)
     rates.sort()
 
-- 
cgit