3 # Copyright 2008 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 gr, eng_notation, usrp
24 from optparse import OptionParser
25 from gnuradio.eng_option import eng_option
26 from receive_path import receive_path
27 import gnuradio.gr.gr_threading as _threading
30 n2s = eng_notation.num_to_str
32 class status_thread(_threading.Thread):
33 def __init__(self, tb):
34 _threading.Thread.__init__(self)
42 print "Freq. Offset: %5.0f Hz Timing Offset: %5.1f ppm Estimated SNR: %4.1f dB BER: %g" % (
43 tb.frequency_offset(), tb.timing_offset()*1e6, tb.snr(), tb.ber())
46 except KeyboardInterrupt:
49 class rx_bpsk_block(gr.top_block):
50 def __init__(self, options):
52 gr.top_block.__init__(self, "rx_mpsk")
54 print "USRP decimation rate", options.decim_rate
56 # Create a USRP source at desired board, sample rate, frequency, and gain
57 self._setup_usrp(options.which,
59 options.rx_subdev_spec,
63 # Create the BERT receiver
64 if_rate = self._usrp.adc_rate()/options.decim_rate
65 self._receiver = receive_path(if_rate,
72 options.mm_gain_omega,
73 options.mm_omega_limit)
75 self.connect(self._usrp, self._receiver)
78 def _setup_usrp(self, which, decim, subdev_spec, freq, gain):
79 self._usrp = usrp.source_c(which=which, decim_rate=decim)
80 if subdev_spec is None:
81 subdev_spec = usrp.pick_rx_subdevice(self._usrp)
82 self._subdev = usrp.selected_subdev(self._usrp, subdev_spec)
83 mux = usrp.determine_rx_mux_value(self._usrp, subdev_spec)
84 self._usrp.set_mux(mux)
85 tr = self._usrp.tune(0, self._subdev, freq)
87 print "Failed to tune to center frequency!"
89 print "Center frequency:", n2s(freq)
91 g = self._subdev.gain_range();
92 gain = float(g[0]+g[1])/2.0
93 self._subdev.set_gain(gain)
94 print "RX d'board:", self._subdev.side_and_name()
97 return self._receiver.snr()
100 return self._receiver.signal_mean()
103 return self._receiver.noise_variance()
106 return self._receiver.ber()
108 def frequency_offset(self):
109 return self._receiver.frequency_offset()
111 def timing_offset(self):
112 return self._receiver.timing_offset()
115 parser = OptionParser(option_class=eng_option)
116 parser.add_option("-w", "--which", type="int", default=0,
117 help="select which USRP (0, 1, ...) (default is %default)",
119 parser.add_option("-R", "--rx-subdev-spec", type="subdev", default=None,
120 help="select USRP Rx side A or B (default=first one with a daughterboard)")
121 parser.add_option("-f", "--freq", type="eng_float", default=None,
122 help="set frequency to FREQ", metavar="FREQ")
123 parser.add_option("-g", "--gain", type="eng_float", default=None,
124 help="set Rx gain (default is mid-point)")
125 parser.add_option("-r", "--rate", type="eng_float", default=250e3,
126 help="Select modulation symbol rate (default=%default)")
127 parser.add_option("-d", "--decim-rate", type="int", default=8,
128 help="Select USRP decimation rate (default=%default)")
129 parser.add_option("", "--excess-bw", type="eng_float", default=0.35,
130 help="Select RRC excess bandwidth (default=%default)")
131 parser.add_option("", "--costas-alpha", type="eng_float", default=0.05,
132 help="set Costas loop 1st order gain, (default=%default)")
133 parser.add_option("", "--costas-beta", type="eng_float", default=0.00025,
134 help="set Costas loop 2nd order gain, (default=%default)")
135 parser.add_option("", "--costas-max", type="eng_float", default=0.05,
136 help="set Costas loop max freq (rad/sample) (default=%default)")
137 parser.add_option("", "--mm-gain-mu", type="eng_float", default=0.001,
138 help="set M&M loop 1st order gain, (default=%default)")
139 parser.add_option("", "--mm-gain-omega", type="eng_float", default=0.000001,
140 help="set M&M loop 2nd order gain, (default=%default)")
141 parser.add_option("", "--mm-omega-limit", type="eng_float", default=0.0001,
142 help="set M&M max timing error, (default=%default)")
145 (options, args) = parser.parse_args()
150 if options.freq == None:
151 print "You must supply a frequency with -f or --freq"
154 return (options, args)
157 if __name__ == "__main__":
158 (options, args) = get_options()
160 tb = rx_bpsk_block(options)
162 print "\n*** SNR estimator is inaccurate below about 7dB"
163 print "*** BER estimator is inaccurate above about 10%\n"
164 updater = status_thread(tb)
168 except KeyboardInterrupt: