4 # Copyright 2005, 2006,2007 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 3, 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_block2):
37 def __init__(self, sample_rate, noise_voltage, frequency_offset, seed=False):
38 gr.hier_block2.__init__(self, "awgn_channel",
39 gr.io_signature(1,1,gr.sizeof_gr_complex), # Input signature
40 gr.io_signature(1,1,gr.sizeof_gr_complex)) # Output signature
42 # Create the Gaussian noise source
44 self.noise = gr.noise_source_c(gr.GR_GAUSSIAN, noise_voltage)
46 rseed = int(time.time())
47 self.noise = gr.noise_source_c(gr.GR_GAUSSIAN, noise_voltage, rseed)
48 self.adder = gr.add_cc()
50 # Create the frequency offset
51 self.offset = gr.sig_source_c((sample_rate*1.0), gr.GR_SIN_WAVE, frequency_offset, 1.0, 0.0)
52 self.mixer = gr.multiply_cc()
54 # Connect the components
55 self.connect(self, (self.mixer, 0))
56 self.connect(self.offset, (self.mixer, 1))
57 self.connect(self.mixer, (self.adder, 0))
58 self.connect(self.noise, (self.adder, 1))
59 self.connect(self.adder, self)
62 class my_graph(gr.top_block):
63 def __init__(self, mod_class, demod_class, rx_callback, options):
64 gr.top_block.__init__(self, "my_graph")
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(mod_class, options)
76 self.throttle = gr.throttle(gr.sizeof_gr_complex, options.sample_rate)
77 self.rxpath = receive_path(demod_class, rx_callback, options)
80 self.channel = awgn_channel(options.sample_rate, noise_voltage, frequency_offset, options.seed)
81 self.connect(self.txpath, self.throttle, self.channel, self.rxpath)
83 self.connect(self.txpath, self.throttle, self.rxpath)
85 # /////////////////////////////////////////////////////////////////////////////
87 # /////////////////////////////////////////////////////////////////////////////
91 global n_rcvd, n_right
96 def rx_callback(ok, payload):
97 global n_rcvd, n_right
98 (pktno,) = struct.unpack('!H', payload[0:2])
103 print "ok = %5s pktno = %4d n_rcvd = %4d n_right = %4d" % (
104 ok, pktno, n_rcvd, n_right)
106 def send_pkt(payload='', eof=False):
107 return top_block.txpath.send_pkt(payload, eof)
110 mods = modulation_utils.type_1_mods()
111 demods = modulation_utils.type_1_demods()
113 parser = OptionParser(option_class=eng_option, conflict_handler="resolve")
114 expert_grp = parser.add_option_group("Expert")
115 channel_grp = parser.add_option_group("Channel")
117 parser.add_option("-m", "--modulation", type="choice", choices=mods.keys(),
119 help="Select modulation from: %s [default=%%default]"
120 % (', '.join(mods.keys()),))
122 parser.add_option("-s", "--size", type="eng_float", default=1500,
123 help="set packet size [default=%default]")
124 parser.add_option("-M", "--megabytes", type="eng_float", default=1.0,
125 help="set megabytes to transmit [default=%default]")
126 parser.add_option("","--discontinuous", action="store_true", default=False,
127 help="enable discontinous transmission (bursts of 5 packets)")
129 channel_grp.add_option("", "--sample-rate", type="eng_float", default=1e5,
130 help="set speed of channel/simulation rate to RATE [default=%default]")
131 channel_grp.add_option("", "--snr", type="eng_float", default=30,
132 help="set the SNR of the channel in dB [default=%default]")
133 channel_grp.add_option("", "--frequency-offset", type="eng_float", default=0,
134 help="set frequency offset introduced by channel [default=%default]")
135 channel_grp.add_option("", "--seed", action="store_true", default=False,
136 help="use a random seed for AWGN noise [default=%default]")
138 transmit_path.add_options(parser, expert_grp)
139 receive_path.add_options(parser, expert_grp)
141 for mod in mods.values():
142 mod.add_options(expert_grp)
143 for demod in demods.values():
144 demod.add_options(expert_grp)
146 (options, args) = parser.parse_args ()
152 r = gr.enable_realtime_scheduling()
154 print "Warning: failed to enable realtime scheduling"
156 # Create an instance of a hierarchical block
157 top_block = my_graph(mods[options.modulation], demods[options.modulation], rx_callback, options)
160 # generate and send packets
161 nbytes = int(1e6 * options.megabytes)
164 pkt_size = int(options.size)
167 send_pkt(struct.pack('!H', pktno) + (pkt_size - 2) * chr(pktno & 0xff))
169 if options.discontinuous and pktno % 5 == 4:
177 if __name__ == '__main__':
180 except KeyboardInterrupt: