3 from gnuradio import gr, blks
4 from gnuradio.eng_option import eng_option
5 from optparse import OptionParser
11 #raw_input('Attach and press enter')
14 class my_graph(gr.flow_graph):
16 def __init__(self, rx_callback, spb, bt, SNR, freq_error):
17 gr.flow_graph.__init__(self)
23 omega = spb*(1+freq_error)
26 self.packet_transmitter = blks.gmsk2_mod_pkts(fg, spb=spb, bt=bt)
30 noise = gr.noise_source_c(gr.GR_GAUSSIAN, pow(10.0,-SNR/20.0))
33 rx_filt_taps = gr.firdes.low_pass(1,spb,0.8,0.1,gr.firdes.WIN_HANN)
34 rx_filt = gr.fir_filter_ccf(1,rx_filt_taps)
37 self.packet_receiver = blks.gmsk2_demod_pkts(fg, callback=rx_callback,
38 spb=spb, gain_mu=gain_mu,
39 freq_error=freq_error, omega=omega)
41 fg.connect (self.packet_transmitter, (add,0))
42 fg.connect (noise, (add,1))
43 fg.connect(add, rx_filt, self.packet_receiver)
54 def send_pkt(payload='', eof=False):
55 fg.packet_transmitter.send_pkt(payload, eof)
57 def rx_callback(ok, payload):
61 if len(payload) <= 16:
62 print "ok = %5r payload = '%s' %d/%d" % (ok, payload, st.nright, st.npkts)
64 (pktno,) = struct.unpack('!H', payload[0:2])
65 print "ok = %5r pktno = %4d len(payload) = %4d %d/%d" % (ok, pktno, len(payload),
69 parser = OptionParser (option_class=eng_option)
70 parser.add_option("-M", "--megabytes", type="eng_float", default=1,
71 help="set megabytes to transmit [default=%default]")
72 parser.add_option("-s", "--size", type="eng_float", default=1500,
73 help="set packet size [default=%default]")
74 parser.add_option("","--spb", type=int, default=4,
75 help="set samples per baud to SPB [default=%default]")
76 parser.add_option("", "--bt", type="eng_float", default=0.3,
77 help="set bandwidth time product for Gaussian filter [default=%default]")
78 parser.add_option("", "--snr", type="eng_float", default=20,
79 help="set SNR in dB for simulation [default=%default]")
80 parser.add_option("", "--freq-error", type="eng_float", default=0,
81 help="set frequency error for simulation [default=%default]")
82 (options, args) = parser.parse_args ()
88 pkt_size = int(options.size)
90 fg = my_graph(rx_callback, options.spb, options.bt, options.snr, options.freq_error)
93 nbytes = int(1e6 * options.megabytes)
97 send_pkt('Hello World')
99 # generate and send packets
101 send_pkt(struct.pack('!H', pktno) + (pkt_size - 2) * chr(pktno & 0xff))
105 send_pkt('Goodbye World')
106 send_pkt(eof=True) # tell modulator we're not sending any more pkts
111 if __name__ == '__main__':
114 except KeyboardInterrupt: