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#!/usr/bin/env python
#
# Copyright 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 3, 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, blks
from gnuradio import eng_notation
from gnuradio.eng_option import eng_option
from optparse import OptionParser
import random, time, struct, sys, math, os
# from current dir
from transmit_path import transmit_path
from receive_path import receive_path
class my_graph(gr.flow_graph):
def __init__(self, callback, options):
gr.flow_graph.__init__(self)
if not options.channel_off:
SNR = 10.0**(options.snr/10.0)
power_in_signal = abs(options.tx_amplitude)**2.0
noise_power_in_channel = power_in_signal/SNR
noise_voltage = math.sqrt(noise_power_in_channel/2.0)
print "Noise voltage: ", noise_voltage
frequency_offset = options.frequency_offset / options.fft_length
print "Frequency offset: ", frequency_offset
if options.multipath_on:
taps = [1.0, .2, 0.0, .1, .08, -.4, .12, -.2, 0, 0, 0, .3]
else:
taps = [1.0, 0.0]
else:
noise_voltage = 0.0
frequency_offset = 0.0
taps = [1.0, 0.0]
symbols_per_packet = math.ceil(((4+options.size+4) * 8) / options.occupied_tones)
samples_per_packet = (symbols_per_packet+2) * (options.fft_length+options.cp_length)
print "Symbols per Packet: ", symbols_per_packet
print "Samples per Packet: ", samples_per_packet
if options.discontinuous:
stream_size = [100000, int(options.discontinuous*samples_per_packet)]
else:
stream_size = [0, 100000]
z = [0,]
self.zeros = gr.vector_source_c(z, True)
self.txpath = transmit_path(self, options)
self.mux = gr.stream_mux(gr.sizeof_gr_complex, stream_size)
self.throttle = gr.throttle(gr.sizeof_gr_complex, options.sample_rate)
self.channel = blks.channel_model(self, noise_voltage, frequency_offset,
options.clockrate_ratio, taps)
self.rxpath = receive_path(self, callback, options)
self.connect(self.zeros, (self.mux,0))
self.connect(self.txpath, (self.mux,1))
self.connect(self.mux, self.throttle, self.channel, self.rxpath)
if options.log:
self.connect(self.txpath, gr.file_sink(gr.sizeof_gr_complex, "txpath.dat"))
self.connect(self.mux, gr.file_sink(gr.sizeof_gr_complex, "mux.dat"))
self.connect(self.channel, gr.file_sink(gr.sizeof_gr_complex, "channel.dat"))
# /////////////////////////////////////////////////////////////////////////////
# main
# /////////////////////////////////////////////////////////////////////////////
def main():
global n_rcvd, n_right
n_rcvd = 0
n_right = 0
def send_pkt(payload='', eof=False):
return fg.txpath.send_pkt(payload, eof)
def rx_callback(ok, payload):
global n_rcvd, n_right
n_rcvd += 1
(pktno,) = struct.unpack('!H', payload[0:2])
if ok:
n_right += 1
print "ok: %r \t pktno: %d \t n_rcvd: %d \t n_right: %d" % (ok, pktno, n_rcvd, n_right)
printlst = list()
for x in payload[2:]:
t = hex(ord(x)).replace('0x', '')
if(len(t) == 1):
t = '0' + t
printlst.append(t)
printable = ''.join(printlst)
print printable
print "\n"
parser = OptionParser(option_class=eng_option, conflict_handler="resolve")
expert_grp = parser.add_option_group("Expert")
parser.add_option("-s", "--size", type="eng_float", default=400,
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("-r", "--sample-rate", type="eng_float", default=1e5,
help="limit sample rate to RATE in throttle (%default)")
parser.add_option("", "--snr", type="eng_float", default=30,
help="set the SNR of the channel in dB [default=%default]")
parser.add_option("", "--frequency-offset", type="eng_float", default=0,
help="set frequency offset introduced by channel [default=%default]")
parser.add_option("", "--clockrate-ratio", type="eng_float", default=1.0,
help="set clock rate ratio (sample rate difference) between two systems [default=%default]")
parser.add_option("","--discontinuous", type="int", default=0,
help="enable discontinous transmission, burst of N packets [Default is continuous]")
parser.add_option("","--channel-off", action="store_true", default=False,
help="Turns AWGN, freq offset channel off")
parser.add_option("","--multipath-on", action="store_true", default=False,
help="enable multipath")
transmit_path.add_options(parser, expert_grp)
receive_path.add_options(parser, expert_grp)
blks.ofdm_mod.add_options(parser, expert_grp)
blks.ofdm_demod.add_options(parser, expert_grp)
(options, args) = parser.parse_args ()
# build the graph
fg = my_graph(rx_callback, options)
r = gr.enable_realtime_scheduling()
# if r != gr.RT_OK:
# print "Warning: failed to enable realtime scheduling"
fg.start() # start flow graph
# generate and send packets
nbytes = int(1e6 * options.megabytes)
n = 0
pktno = 0
pkt_size = int(options.size)
while n < nbytes:
#r = ''.join([chr(random.randint(0,255)) for i in range(pkt_size-2)])
#pkt_contents = struct.pack('!H', pktno) + r
pkt_contents = struct.pack('!H', pktno) + (pkt_size - 2) * chr(pktno & 0xff)
send_pkt(pkt_contents)
n += pkt_size
#sys.stderr.write('.')
#if options.discontinuous and pktno % 5 == 4:
# time.sleep(1)
pktno += 1
send_pkt(eof=True)
fg.wait() # wait for it to finish
if __name__ == '__main__':
try:
main()
except KeyboardInterrupt:
pass
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