4 # Copyright 2005, 2006 Free Software Foundation, Inc.
6 # This file is part of GNU Radio
8 # GNU Radio is free software; you can redistribute it and/or modify
9 # it under the terms of the GNU General Public License as published by
10 # the Free Software Foundation; either version 2, or (at your option)
13 # GNU Radio is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with GNU Radio; see the file COPYING. If not, write to
20 # the Free Software Foundation, Inc., 51 Franklin Street,
21 # Boston, MA 02110-1301, USA.
24 from gnuradio import gr, gru, modulation_utils
25 from gnuradio import eng_notation
26 from gnuradio.eng_option import eng_option
27 from optparse import OptionParser
29 import random, time, struct, sys, math
32 from transmit_path_lb import transmit_path
33 from receive_path_lb import receive_path
36 class awgn_channel(gr.hier_block):
37 def __init__(self, fg, sample_rate, noise_voltage, frequency_offset, seed=False):
38 self.input = gr.add_const_cc(0) # dummy input device
40 # Create the Gaussian noise source
42 self.noise = gr.noise_source_c(gr.GR_GAUSSIAN, noise_voltage)
44 rseed = int(time.time())
45 self.noise = gr.noise_source_c(gr.GR_GAUSSIAN, noise_voltage, rseed)
47 self.adder = gr.add_cc()
49 # Create the frequency offset
50 self.offset = gr.sig_source_c(1, gr.GR_SIN_WAVE,
51 frequency_offset, 1.0, 0.0)
52 self.mixer = gr.multiply_cc()
54 # Connect the components
55 fg.connect(self.input, (self.mixer, 0))
56 fg.connect(self.offset, (self.mixer, 1))
57 fg.connect(self.mixer, (self.adder, 0))
58 fg.connect(self.noise, (self.adder, 1))
60 gr.hier_block.__init__(self, fg, self.input, self.adder)
62 class my_graph(gr.flow_graph):
63 def __init__(self, mod_class, demod_class, rx_callback, options):
64 gr.flow_graph.__init__(self)
68 SNR = 10.0**(options.snr/10.0)
69 frequency_offset = options.frequency_offset
71 power_in_signal = abs(options.tx_amplitude)**2
72 noise_power = power_in_signal/SNR
73 noise_voltage = math.sqrt(noise_power)
75 self.txpath = transmit_path(self, mod_class, options)
76 self.throttle = gr.throttle(gr.sizeof_gr_complex, options.sample_rate)
77 self.rxpath = receive_path(self, demod_class, rx_callback, options)
80 self.channel = awgn_channel(self, options.sample_rate, noise_voltage, frequency_offset, options.seed)
83 self.connect(self.txpath, self.throttle, self.channel, self.rxpath)
86 self.connect(self.txpath, self.throttle, self.rxpath)
89 # /////////////////////////////////////////////////////////////////////////////
91 # /////////////////////////////////////////////////////////////////////////////
95 global n_rcvd, n_right
100 def rx_callback(ok, payload):
101 global n_rcvd, n_right
102 (pktno,) = struct.unpack('!H', payload[0:2])
107 print "ok = %5s pktno = %4d n_rcvd = %4d n_right = %4d" % (
108 ok, pktno, n_rcvd, n_right)
110 def send_pkt(payload='', eof=False):
111 return fg.txpath.send_pkt(payload, eof)
114 mods = modulation_utils.type_1_mods()
115 demods = modulation_utils.type_1_demods()
117 parser = OptionParser(option_class=eng_option, conflict_handler="resolve")
118 expert_grp = parser.add_option_group("Expert")
119 channel_grp = parser.add_option_group("Channel")
121 parser.add_option("-m", "--modulation", type="choice", choices=mods.keys(),
123 help="Select modulation from: %s [default=%%default]"
124 % (', '.join(mods.keys()),))
126 parser.add_option("-s", "--size", type="eng_float", default=1500,
127 help="set packet size [default=%default]")
128 parser.add_option("-M", "--megabytes", type="eng_float", default=1.0,
129 help="set megabytes to transmit [default=%default]")
130 parser.add_option("","--discontinuous", action="store_true", default=False,
131 help="enable discontinous transmission (bursts of 5 packets)")
133 channel_grp.add_option("", "--sample-rate", type="eng_float", default=1e5,
134 help="set speed of channel/simulation rate to RATE [default=%default]")
135 channel_grp.add_option("", "--snr", type="eng_float", default=30,
136 help="set the SNR of the channel in dB [default=%default]")
137 channel_grp.add_option("", "--frequency-offset", type="eng_float", default=0,
138 help="set frequency offset introduced by channel [default=%default]")
139 channel_grp.add_option("", "--seed", action="store_true", default=False,
140 help="use a random seed for AWGN noise [default=%default]")
142 transmit_path.add_options(parser, expert_grp)
143 receive_path.add_options(parser, expert_grp)
145 for mod in mods.values():
146 mod.add_options(expert_grp)
147 for demod in demods.values():
148 demod.add_options(expert_grp)
150 (options, args) = parser.parse_args ()
156 r = gr.enable_realtime_scheduling()
158 print "Warning: failed to enable realtime scheduling"
160 # Create an instance of a hierarchical block
161 fg = my_graph(mods[options.modulation], demods[options.modulation], rx_callback, options)
164 # generate and send packets
165 nbytes = int(1e6 * options.megabytes)
168 pkt_size = int(options.size)
171 send_pkt(struct.pack('!H', pktno) + (pkt_size - 2) * chr(pktno & 0xff))
173 if options.discontinuous and pktno % 5 == 4:
181 if __name__ == '__main__':
184 except KeyboardInterrupt: