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| author | Josh Blum <josh@joshknows.com> | 2011-08-17 11:56:33 -0700 |
|---|---|---|
| committer | Josh Blum <josh@joshknows.com> | 2011-08-17 11:56:33 -0700 |
| commit | e6ed4fa7bb0d253adbf0cf2ae4da7c301b3c971f (patch) | |
| tree | 09f43f64f581af7b5159debaf7489365b0a1259d /gr-digital/examples/example_costas.py | |
| parent | 40a9071074b2ec0f6daf74e50e131b89b9f66226 (diff) | |
| parent | ed564be6c78a3e22b3c98862834192f8b20bc551 (diff) | |
Merge branch 'digital' of https://github.com/trondeau/gnuradio into digital
Conflicts:
gnuradio-core/src/lib/filter/gr_pfb_clock_sync_ccf.h
gnuradio-core/src/lib/general/gr_fll_band_edge_cc.h
gnuradio-core/src/lib/general/gr_pll_refout_cc.h
gr-digital/lib/digital_constellation_receiver_cb.cc
gr-digital/lib/digital_constellation_receiver_cb.h
gr-digital/lib/digital_costas_loop_cc.h
Diffstat (limited to 'gr-digital/examples/example_costas.py')
| -rwxr-xr-x | gr-digital/examples/example_costas.py | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/gr-digital/examples/example_costas.py b/gr-digital/examples/example_costas.py new file mode 100755 index 0000000000..aef0196cc0 --- /dev/null +++ b/gr-digital/examples/example_costas.py @@ -0,0 +1,116 @@ +#!/usr/bin/env python + +from gnuradio import gr, digital +from gnuradio import eng_notation +from gnuradio.eng_option import eng_option +from optparse import OptionParser + +try: + import scipy +except ImportError: + print "Error: could not import scipy (http://www.scipy.org/)" + sys.exit(1) + +try: + import pylab +except ImportError: + print "Error: could not import pylab (http://matplotlib.sourceforge.net/)" + sys.exit(1) + +class example_costas(gr.top_block): + def __init__(self, N, sps, rolloff, ntaps, bw, noise, foffset, toffset, poffset): + gr.top_block.__init__(self) + + rrc_taps = gr.firdes.root_raised_cosine( + sps, sps, 1.0, rolloff, ntaps) + + data = 2.0*scipy.random.randint(0, 2, N) - 1.0 + data = scipy.exp(1j*poffset) * data + + self.src = gr.vector_source_c(data.tolist(), False) + self.rrc = gr.interp_fir_filter_ccf(sps, rrc_taps) + self.chn = gr.channel_model(noise, foffset, toffset) + self.cst = digital.costas_loop_cc(bw, 2) + + self.vsnk_src = gr.vector_sink_c() + self.vsnk_cst = gr.vector_sink_c() + self.vsnk_frq = gr.vector_sink_f() + + self.connect(self.src, self.rrc, self.chn, self.cst, self.vsnk_cst) + self.connect(self.rrc, self.vsnk_src) + self.connect((self.cst,1), self.vsnk_frq) + +def main(): + parser = OptionParser(option_class=eng_option, conflict_handler="resolve") + parser.add_option("-N", "--nsamples", type="int", default=2000, + help="Set the number of samples to process [default=%default]") + parser.add_option("-S", "--sps", type="int", default=4, + help="Set the samples per symbol [default=%default]") + parser.add_option("-r", "--rolloff", type="eng_float", default=0.35, + help="Set the rolloff factor [default=%default]") + parser.add_option("-W", "--bandwidth", type="eng_float", default=2*scipy.pi/100.0, + help="Set the loop bandwidth [default=%default]") + parser.add_option("-n", "--ntaps", type="int", default=45, + help="Set the number of taps in the filters [default=%default]") + parser.add_option("", "--noise", type="eng_float", default=0.0, + help="Set the simulation noise voltage [default=%default]") + parser.add_option("-f", "--foffset", type="eng_float", default=0.0, + help="Set the simulation's normalized frequency offset (in Hz) [default=%default]") + parser.add_option("-t", "--toffset", type="eng_float", default=1.0, + help="Set the simulation's timing offset [default=%default]") + parser.add_option("-p", "--poffset", type="eng_float", default=0.707, + help="Set the simulation's phase offset [default=%default]") + (options, args) = parser.parse_args () + + # Adjust N for the interpolation by sps + options.nsamples = options.nsamples // options.sps + + # Set up the program-under-test + put = example_costas(options.nsamples, options.sps, options.rolloff, + options.ntaps, options.bandwidth, options.noise, + options.foffset, options.toffset, options.poffset) + put.run() + + data_src = scipy.array(put.vsnk_src.data()) + + # Convert the FLL's LO frequency from rads/sec to Hz + data_frq = scipy.array(put.vsnk_frq.data()) / (2.0*scipy.pi) + + # adjust this to align with the data. + data_cst = scipy.array(3*[0,]+list(put.vsnk_cst.data())) + + # Plot the Costas loop's LO frequency + f1 = pylab.figure(1, figsize=(12,10), facecolor='w') + s1 = f1.add_subplot(2,2,1) + s1.plot(data_frq) + s1.set_title("Costas LO") + s1.set_xlabel("Samples") + s1.set_ylabel("Frequency (normalized Hz)") + + # Plot the IQ symbols + s3 = f1.add_subplot(2,2,2) + s3.plot(data_src.real, data_src.imag, "o") + s3.plot(data_cst.real, data_cst.imag, "rx") + s3.set_title("IQ") + s3.set_xlabel("Real part") + s3.set_ylabel("Imag part") + s3.set_xlim([-2, 2]) + s3.set_ylim([-2, 2]) + + # Plot the symbols in time + s4 = f1.add_subplot(2,2,3) + s4.set_position([0.125, 0.05, 0.775, 0.4]) + s4.plot(data_src.real, "o-") + s4.plot(data_cst.real, "rx-") + s4.set_title("Symbols") + s4.set_xlabel("Samples") + s4.set_ylabel("Real Part of Signals") + + pylab.show() + +if __name__ == "__main__": + try: + main() + except KeyboardInterrupt: + pass + |