2 # Copyright 2005,2006 Free Software Foundation, Inc.
4 # This file is part of GNU Radio
6 # GNU Radio is free software; you can redistribute it and/or modify
7 # it under the terms of the GNU General Public License as published by
8 # the Free Software Foundation; either version 3, or (at your option)
11 # GNU Radio is distributed in the hope that it will be useful,
12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 # GNU General Public License for more details.
16 # You should have received a copy of the GNU General Public License
17 # along with GNU Radio; see the file COPYING. If not, write to
18 # the Free Software Foundation, Inc., 51 Franklin Street,
19 # Boston, MA 02110-1301, USA.
22 from gnuradio import eng_notation
24 _default_bitrate = 500e3
26 _valid_samples_per_symbol = (2,3,4,5,6,7)
28 def _gen_tx_info(converter_rate, xrates):
30 for samples_per_symbol in _valid_samples_per_symbol:
32 bitrate = converter_rate / interp / samples_per_symbol
33 results.append((bitrate, samples_per_symbol, interp))
37 def _gen_rx_info(converter_rate, xrates):
39 for samples_per_symbol in _valid_samples_per_symbol:
41 bitrate = converter_rate / decim / samples_per_symbol
42 results.append((bitrate, samples_per_symbol, decim))
46 def _filter_info(info, samples_per_symbol, xrate):
47 if samples_per_symbol is not None:
48 info = [x for x in info if x[1] == samples_per_symbol]
50 info = [x for x in info if x[2] == xrate]
53 def _pick_best(target_bitrate, bits_per_symbol, info):
55 @returns tuple (bitrate, samples_per_symbol, interp_rate_or_decim_rate)
58 raise RuntimeError, "info is zero length!"
60 if target_bitrate is None: # return the fastest one
63 # convert bit rate to symbol rate
64 target_symbolrate = target_bitrate / bits_per_symbol
66 # Find the closest matching symbol rate.
67 # In the event of a tie, the one with the lowest samples_per_symbol wins.
68 # (We already sorted them, so the first one is the one we take)
71 best_delta = abs(target_symbolrate - best[0])
73 delta = abs(target_symbolrate - x[0])
74 if delta < best_delta:
78 # convert symbol rate back to bit rate
79 return ((best[0] * bits_per_symbol),) + best[1:]
81 def _pick_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
82 xrate, converter_rate, xrates, gen_info):
84 @returns tuple (bitrate, samples_per_symbol, interp_rate_or_decim_rate)
86 if not isinstance(bits_per_symbol, int) or bits_per_symbol < 1:
87 raise ValueError, "bits_per_symbol must be an int >= 1"
89 if samples_per_symbol is not None and xrate is not None: # completely determined
90 return (float(converter_rate) / xrate / samples_per_symbol,
91 samples_per_symbol, xrate)
93 if bitrate is None and samples_per_symbol is None and xrate is None:
94 bitrate = _default_bitrate
96 # now we have a target bitrate and possibly an xrate or
97 # samples_per_symbol constraint, but not both of them.
99 ret = _pick_best(bitrate, bits_per_symbol,
100 _filter_info(gen_info(converter_rate, xrates), samples_per_symbol, xrate))
101 print "Actual Bitrate:", eng_notation.num_to_str(ret[0])
104 # ---------------------------------------------------------------------------------------
106 def pick_tx_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
107 interp_rate, converter_rate, possible_interps):
109 Given the 4 input parameters, return at configuration that matches
111 @param bitrate: desired bitrate or None
112 @type bitrate: number or None
113 @param bits_per_symbol: E.g., BPSK -> 1, QPSK -> 2, 8-PSK -> 3
114 @type bits_per_symbol: integer >= 1
115 @param samples_per_symbol: samples/baud (aka samples/symbol)
116 @type samples_per_symbol: number or None
117 @param interp_rate: USRP interpolation factor
118 @type interp_rate: integer or None
119 @param converter_rate: converter sample rate in Hz
120 @type converter_rate: number
121 @param possible_interps: a list of possible rates
122 @type possible_interps: a list of integers
124 @returns tuple (bitrate, samples_per_symbol, interp_rate)
126 print "Requested TX Bitrate:", bitrate and eng_notation.num_to_str(bitrate) or 'Auto',
127 return _pick_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
128 interp_rate, converter_rate, possible_interps, _gen_tx_info)
131 def pick_rx_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
132 decim_rate, converter_rate, possible_decims):
134 Given the 4 input parameters, return at configuration that matches
136 @param bitrate: desired bitrate or None
137 @type bitrate: number or None
138 @param bits_per_symbol: E.g., BPSK -> 1, QPSK -> 2, 8-PSK -> 3
139 @type bits_per_symbol: integer >= 1
140 @param samples_per_symbol: samples/baud (aka samples/symbol)
141 @type samples_per_symbol: number or None
142 @param decim_rate: USRP decimation factor
143 @type decim_rate: integer or None
144 @param converter_rate: converter sample rate in Hz
145 @type converter_rate: number
146 @param possible_decims: a list of possible rates
147 @type possible_decims: a list of integers
149 @returns tuple (bitrate, samples_per_symbol, decim_rate)
151 print "Requested RX Bitrate:", bitrate and eng_notation.num_to_str(bitrate) or 'Auto'
152 return _pick_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
153 decim_rate, converter_rate, possible_decims, _gen_rx_info)