git.gag.com Git - debian/gnuradio/blob - gnuradio-examples/python/gmsk2/mpsk_test.py

   1 #!/usr/bin/env python
   2
   3 from gnuradio import gr, blks
   4 from gnuradio.eng_option import eng_option
   5 from optparse import OptionParser
   6 import random
   7 import struct
   8 from mpsk_pkt import *
   9 import cmath
  10
  11 class my_graph(gr.flow_graph):
  12
  13     def __init__(self, rx_callback, spb, excess_bw, SNR, freq_error, arity):
  14         gr.flow_graph.__init__(self)
  15
  16         fg = self
  17
  18         # Tuning Parameters
  19         gain_mu = 0.05/spb
  20
  21         # transmitter
  22         self.packet_transmitter = \
  23           mpsk_mod_pkts(fg, spb=spb, excess_bw=excess_bw, diff=True, arity=arity)
  24
  25         # ----------------------------------------------------------------
  26         #                       Channel model
  27         # ----------------------------------------------------------------
  28
  29         awgn = gr.noise_source_c(gr.GR_GAUSSIAN, pow(10.0,-SNR/20.0))
  30         add = gr.add_cc()            # add some noise
  31         fg.connect(awgn, (add,1))
  32         radians = 17*pi/180
  33         phase_rotate = gr.multiply_const_cc(cmath.exp(radians * 1j))
  34
  35         # ----------------------------------------------------------------
  36
  37         # channel filter
  38         rx_filt_taps = gr.firdes.low_pass(1,spb,0.8,0.1,gr.firdes.WIN_HANN)
  39         #rx_filt_taps = (1,)
  40         rx_filt = gr.fir_filter_ccf(1,rx_filt_taps)
  41
  42         # receiver
  43         self.packet_receiver = \
  44             mpsk_demod_pkts(fg, callback=rx_callback,
  45                             excess_bw=excess_bw, arity=arity, diff=True,
  46                             costas_alpha=.005, gain_mu=gain_mu, spb=spb)
  47
  48         fg.connect (self.packet_transmitter, (add,0))
  49         fg.connect(add, phase_rotate, rx_filt, self.packet_receiver)
  50
  51
  52 class stats(object):
  53     def __init__(self):
  54         self.npkts = 0
  55         self.nright = 0
  56
  57 def main():
  58     st = stats()
  59
  60     def send_pkt(payload='', eof=False):
  61         fg.packet_transmitter.send_pkt(payload, eof)
  62
  63     def rx_callback(ok, payload):
  64         st.npkts += 1
  65         if ok:
  66             st.nright += 1
  67         if len(payload) <= 16:
  68             print "ok = %5r  payload = '%s'  %d/%d" % (ok, payload, st.nright, st.npkts)
  69         else:
  70             (pktno,) = struct.unpack('!H', payload[0:2])
  71             print "ok = %5r  pktno = %4d  len(payload) = %4d  %d/%d" % (ok, pktno, len(payload),
  72                                                                         st.nright, st.npkts)
  73
  74
  75     parser = OptionParser (option_class=eng_option)
  76     parser.add_option("-M", "--megabytes", type="eng_float", default=1,
  77                       help="set megabytes to transmit [default=%default]")
  78     parser.add_option("-s", "--size", type="eng_float", default=1500,
  79                       help="set packet size [default=%default]")
  80     parser.add_option("","--spb", type=int, default=4,
  81                       help="set samples per baud to SPB [default=%default]")
  82     parser.add_option("", "--excess-bw", type="eng_float", default=0.4,
  83                       help="set excess bandwidth for RRC filter [default=%default]")
  84     parser.add_option("", "--snr", type="eng_float", default=40,
  85                       help="set SNR in dB for simulation [default=%default]")
  86     parser.add_option("", "--m-arity", type=int, default=4,
  87                       help="PSK arity [default=%default]")
  88     parser.add_option("", "--freq-error", type="eng_float", default=0,
  89                       help="set frequency error for simulation [default=%default]")
  90
  91     (options, args) = parser.parse_args ()
  92
  93     if len(args) != 0:
  94         parser.print_help()
  95         sys.exit(1)
  96
  97     pkt_size = int(options.size)
  98
  99     fg = my_graph(rx_callback, options.spb, options.excess_bw, options.snr,
 100                   options.freq_error, options.m_arity)
 101     fg.start()
 102
 103     nbytes = int(1e6 * options.megabytes)
 104     n = 0
 105     pktno = 0
 106
 107     send_pkt('Hello World')
 108
 109     # generate and send packets
 110     while n < nbytes:
 111         send_pkt(struct.pack('!H', pktno) + (pkt_size - 2) * chr(pktno & 0xff))
 112         n += pkt_size
 113         pktno += 1
 114
 115     send_pkt('Goodbye World')
 116     send_pkt(eof=True)             # tell modulator we're not sending any more pkts
 117
 118     fg.wait()
 119
 120
 121 if __name__ == '__main__':
 122     try:
 123         main()
 124     except KeyboardInterrupt:
 125         pass