#!/usr/bin/env python #!/usr/bin/env python # # Copyright 2005, 2006,2007 Free Software Foundation, Inc. # # This file is part of GNU Radio # # GNU Radio is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2, or (at your option) # any later version. # # GNU Radio is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with GNU Radio; see the file COPYING. If not, write to # the Free Software Foundation, Inc., 51 Franklin Street, # Boston, MA 02110-1301, USA. # from gnuradio import gr, gru, modulation_utils from gnuradio import eng_notation from gnuradio.eng_option import eng_option from optparse import OptionParser import random, time, struct, sys, math # from current dir from transmit_path_lb import transmit_path from receive_path_lb import receive_path import fusb_options class awgn_channel(gr.hier_block2): def __init__(self, sample_rate, noise_voltage, frequency_offset, seed=False): gr.hier_block2.__init__(self, "awgn_channel", gr.io_signature(1,1,gr.sizeof_gr_complex), # Input signature gr.io_signature(1,1,gr.sizeof_gr_complex)) # Output signature # Create the Gaussian noise source if not seed: self.noise = gr.noise_source_c(gr.GR_GAUSSIAN, noise_voltage) else: rseed = int(time.time()) self.noise = gr.noise_source_c(gr.GR_GAUSSIAN, noise_voltage, rseed) self.adder = gr.add_cc() # Create the frequency offset self.offset = gr.sig_source_c((sample_rate*1.0), gr.GR_SIN_WAVE, frequency_offset, 1.0, 0.0) self.mixer = gr.multiply_cc() # Connect the components self.connect(self, (self.mixer, 0)) self.connect(self.offset, (self.mixer, 1)) self.connect(self.mixer, (self.adder, 0)) self.connect(self.noise, (self.adder, 1)) self.connect(self.adder, self) class my_graph(gr.top_block): def __init__(self, mod_class, demod_class, rx_callback, options): gr.top_block.__init__(self, "my_graph") channelon = True; SNR = 10.0**(options.snr/10.0) frequency_offset = options.frequency_offset power_in_signal = abs(options.tx_amplitude)**2 noise_power = power_in_signal/SNR noise_voltage = math.sqrt(noise_power) self.txpath = transmit_path(mod_class, options) self.throttle = gr.throttle(gr.sizeof_gr_complex, options.sample_rate) self.rxpath = receive_path(demod_class, rx_callback, options) if channelon: self.channel = awgn_channel(options.sample_rate, noise_voltage, frequency_offset, options.seed) self.connect(self.txpath, self.throttle, self.channel, self.rxpath) else: self.connect(self.txpath, self.throttle, self.rxpath) # ///////////////////////////////////////////////////////////////////////////// # main # ///////////////////////////////////////////////////////////////////////////// def main(): global n_rcvd, n_right n_rcvd = 0 n_right = 0 def rx_callback(ok, payload): global n_rcvd, n_right (pktno,) = struct.unpack('!H', payload[0:2]) n_rcvd += 1 if ok: n_right += 1 print "ok = %5s pktno = %4d n_rcvd = %4d n_right = %4d" % ( ok, pktno, n_rcvd, n_right) def send_pkt(payload='', eof=False): return top_block.txpath.send_pkt(payload, eof) mods = modulation_utils.type_1_mods() demods = modulation_utils.type_1_demods() parser = OptionParser(option_class=eng_option, conflict_handler="resolve") expert_grp = parser.add_option_group("Expert") channel_grp = parser.add_option_group("Channel") parser.add_option("-m", "--modulation", type="choice", choices=mods.keys(), default='dbpsk', help="Select modulation from: %s [default=%%default]" % (', '.join(mods.keys()),)) parser.add_option("-s", "--size", type="eng_float", default=1500, help="set packet size [default=%default]") parser.add_option("-M", "--megabytes", type="eng_float", default=1.0, help="set megabytes to transmit [default=%default]") parser.add_option("","--discontinuous", action="store_true", default=False, help="enable discontinous transmission (bursts of 5 packets)") channel_grp.add_option("", "--sample-rate", type="eng_float", default=1e5, help="set speed of channel/simulation rate to RATE [default=%default]") channel_grp.add_option("", "--snr", type="eng_float", default=30, help="set the SNR of the channel in dB [default=%default]") channel_grp.add_option("", "--frequency-offset", type="eng_float", default=0, help="set frequency offset introduced by channel [default=%default]") channel_grp.add_option("", "--seed", action="store_true", default=False, help="use a random seed for AWGN noise [default=%default]") transmit_path.add_options(parser, expert_grp) receive_path.add_options(parser, expert_grp) for mod in mods.values(): mod.add_options(expert_grp) for demod in demods.values(): demod.add_options(expert_grp) (options, args) = parser.parse_args () if len(args) != 0: parser.print_help() sys.exit(1) r = gr.enable_realtime_scheduling() if r != gr.RT_OK: print "Warning: failed to enable realtime scheduling" # Create an instance of a hierarchical block top_block = my_graph(mods[options.modulation], demods[options.modulation], rx_callback, options) # Create an instance of a runtime, passing it the top block runtime = gr.runtime(top_block) runtime.start() # generate and send packets nbytes = int(1e6 * options.megabytes) n = 0 pktno = 0 pkt_size = int(options.size) while n < nbytes: send_pkt(struct.pack('!H', pktno) + (pkt_size - 2) * chr(pktno & 0xff)) n += pkt_size if options.discontinuous and pktno % 5 == 4: time.sleep(1) pktno += 1 send_pkt(eof=True) runtime.wait() if __name__ == '__main__': try: main() except KeyboardInterrupt: pass