From b845770e33b584a88150dc97b45c7b0807791693 Mon Sep 17 00:00:00 2001 From: Tom Rondeau Date: Wed, 10 Feb 2010 16:12:32 -0800 Subject: [PATCH] Working on pick_bitrate. --- .../python/digital/pick_bitrate2.py | 92 ++++++++++++++----- 1 file changed, 67 insertions(+), 25 deletions(-) diff --git a/gnuradio-examples/python/digital/pick_bitrate2.py b/gnuradio-examples/python/digital/pick_bitrate2.py index c0188dc3..b678f725 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() -- 2.30.2