3 # Copyright 2005,2006 Free Software Foundation, Inc.
5 # This file is part of GNU Radio
7 # GNU Radio is free software; you can redistribute it and/or modify
8 # it under the terms of the GNU General Public License as published by
9 # the Free Software Foundation; either version 3, or (at your option)
12 # GNU Radio is distributed in the hope that it will be useful,
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 # GNU General Public License for more details.
17 # You should have received a copy of the GNU General Public License
18 # along with GNU Radio; see the file COPYING. If not, write to
19 # the Free Software Foundation, Inc., 51 Franklin Street,
20 # Boston, MA 02110-1301, USA.
23 from gnuradio import eng_notation
25 _default_bitrate = 500e3
27 _valid_samples_per_symbol = (2,3,4,5,6,7)
29 def _gen_tx_info(converter_rate, xrates):
31 for samples_per_symbol in _valid_samples_per_symbol:
33 bitrate = converter_rate / interp / samples_per_symbol
34 results.append((bitrate, samples_per_symbol, interp))
38 def _gen_rx_info(converter_rate, xrates):
40 for samples_per_symbol in _valid_samples_per_symbol:
42 bitrate = converter_rate / decim / samples_per_symbol
43 results.append((bitrate, samples_per_symbol, decim))
47 def _filter_info(info, samples_per_symbol, xrate):
48 if samples_per_symbol is not None:
49 info = [x for x in info if x[1] == samples_per_symbol]
51 info = [x for x in info if x[2] == xrate]
54 def _pick_best(target_bitrate, bits_per_symbol, info):
56 @returns tuple (bitrate, samples_per_symbol, interp_rate_or_decim_rate)
59 raise RuntimeError, "info is zero length!"
61 if target_bitrate is None: # return the fastest one
64 # convert bit rate to symbol rate
65 target_symbolrate = target_bitrate / bits_per_symbol
67 # Find the closest matching symbol rate.
68 # In the event of a tie, the one with the lowest samples_per_symbol wins.
69 # (We already sorted them, so the first one is the one we take)
72 best_delta = abs(target_symbolrate - best[0])
74 delta = abs(target_symbolrate - x[0])
75 if delta < best_delta:
79 # convert symbol rate back to bit rate
80 return ((best[0] * bits_per_symbol),) + best[1:]
82 def _pick_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
83 xrate, converter_rate, xrates, gen_info):
85 @returns tuple (bitrate, samples_per_symbol, interp_rate_or_decim_rate)
87 if not isinstance(bits_per_symbol, int) or bits_per_symbol < 1:
88 raise ValueError, "bits_per_symbol must be an int >= 1"
90 if samples_per_symbol is not None and xrate is not None: # completely determined
91 return (float(converter_rate) / xrate / samples_per_symbol,
92 samples_per_symbol, xrate)
94 if bitrate is None and samples_per_symbol is None and xrate is None:
95 bitrate = _default_bitrate
97 # now we have a target bitrate and possibly an xrate or
98 # samples_per_symbol constraint, but not both of them.
100 ret = _pick_best(bitrate, bits_per_symbol,
101 _filter_info(gen_info(converter_rate, xrates), samples_per_symbol, xrate))
102 print "Actual Bitrate:", eng_notation.num_to_str(ret[0])
105 # ---------------------------------------------------------------------------------------
107 def pick_tx_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
108 interp_rate, converter_rate, possible_interps):
110 Given the 4 input parameters, return at configuration that matches
112 @param bitrate: desired bitrate or None
113 @type bitrate: number or None
114 @param bits_per_symbol: E.g., BPSK -> 1, QPSK -> 2, 8-PSK -> 3
115 @type bits_per_symbol: integer >= 1
116 @param samples_per_symbol: samples/baud (aka samples/symbol)
117 @type samples_per_symbol: number or None
118 @param interp_rate: USRP interpolation factor
119 @type interp_rate: integer or None
120 @param converter_rate: converter sample rate in Hz
121 @type converter_rate: number
122 @param possible_interps: a list of possible rates
123 @type possible_interps: a list of integers
125 @returns tuple (bitrate, samples_per_symbol, interp_rate)
127 print "Requested TX Bitrate:", bitrate and eng_notation.num_to_str(bitrate) or 'Auto',
128 return _pick_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
129 interp_rate, converter_rate, possible_interps, _gen_tx_info)
132 def pick_rx_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
133 decim_rate, converter_rate, possible_decims):
135 Given the 4 input parameters, return at configuration that matches
137 @param bitrate: desired bitrate or None
138 @type bitrate: number or None
139 @param bits_per_symbol: E.g., BPSK -> 1, QPSK -> 2, 8-PSK -> 3
140 @type bits_per_symbol: integer >= 1
141 @param samples_per_symbol: samples/baud (aka samples/symbol)
142 @type samples_per_symbol: number or None
143 @param decim_rate: USRP decimation factor
144 @type decim_rate: integer or None
145 @param converter_rate: converter sample rate in Hz
146 @type converter_rate: number
147 @param possible_decims: a list of possible rates
148 @type possible_decims: a list of integers
150 @returns tuple (bitrate, samples_per_symbol, decim_rate)
152 print "Requested RX Bitrate:", bitrate and eng_notation.num_to_str(bitrate) or 'Auto'
153 return _pick_bitrate(bitrate, bits_per_symbol, samples_per_symbol,
154 decim_rate, converter_rate, possible_decims, _gen_rx_info)