X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=gnuradio-examples%2Fpython%2Fpfb%2Fsynth_to_chan.py;fp=gnuradio-examples%2Fpython%2Fpfb%2Fsynth_to_chan.py;h=1beda1a5495d6fb4acfcfa6a96d24085030f3d00;hb=2924c0e740bbb9106bfed602345daaee5606d62a;hp=0000000000000000000000000000000000000000;hpb=94d315e556805fb75784964499472977664809c4;p=debian%2Fgnuradio diff --git a/gnuradio-examples/python/pfb/synth_to_chan.py b/gnuradio-examples/python/pfb/synth_to_chan.py new file mode 100755 index 00000000..1beda1a5 --- /dev/null +++ b/gnuradio-examples/python/pfb/synth_to_chan.py @@ -0,0 +1,105 @@ +#!/usr/bin/env python +# +# Copyright 2010 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, blks2 +import scipy, pylab + +def main(): + N = 1000000 + fs = 8000 + + freqs = [100, 200, 300, 400, 500] + nchans = 7 + + sigs = list() + fmtx = list() + for fi in freqs: + s = gr.sig_source_f(fs, gr.GR_SIN_WAVE, fi, 1) + fm = blks2.nbfm_tx (fs, 4*fs, max_dev=10000, tau=75e-6) + sigs.append(s) + fmtx.append(fm) + + syntaps = gr.firdes.low_pass_2(len(freqs), fs, fs/float(nchans)/2, 100, 100) + print "Synthesis Num. Taps = %d (taps per filter = %d)" % (len(syntaps), + len(syntaps)/nchans) + chtaps = gr.firdes.low_pass_2(len(freqs), fs, fs/float(nchans)/2, 100, 100) + print "Channelizer Num. Taps = %d (taps per filter = %d)" % (len(chtaps), + len(chtaps)/nchans) + filtbank = gr.pfb_synthesis_filterbank_ccf(nchans, syntaps) + channelizer = blks2.pfb_channelizer_ccf(nchans, chtaps) + + noise_level = 0.01 + head = gr.head(gr.sizeof_gr_complex, N) + noise = gr.noise_source_c(gr.GR_GAUSSIAN, noise_level) + addnoise = gr.add_cc() + snk_synth = gr.vector_sink_c() + + tb = gr.top_block() + + tb.connect(noise, (addnoise,0)) + tb.connect(filtbank, head, (addnoise, 1)) + tb.connect(addnoise, channelizer) + tb.connect(addnoise, snk_synth) + + snk = list() + for i,si in enumerate(sigs): + tb.connect(si, fmtx[i], (filtbank, i)) + + for i in xrange(nchans): + snk.append(gr.vector_sink_c()) + tb.connect((channelizer, i), snk[i]) + + tb.run() + + if 1: + channel = 1 + data = snk[channel].data()[1000:] + + f1 = pylab.figure(1) + s1 = f1.add_subplot(1,1,1) + s1.plot(data[10000:10200] ) + s1.set_title(("Output Signal from Channel %d" % channel)) + + fftlen = 2048 + winfunc = scipy.blackman + #winfunc = scipy.hamming + + f2 = pylab.figure(2) + s2 = f2.add_subplot(1,1,1) + s2.psd(data, NFFT=fftlen, + Fs = nchans*fs, + noverlap=fftlen/4, + window = lambda d: d*winfunc(fftlen)) + s2.set_title(("Output PSD from Channel %d" % channel)) + + f3 = pylab.figure(3) + s3 = f3.add_subplot(1,1,1) + s3.psd(snk_synth.data()[1000:], NFFT=fftlen, + Fs = nchans*fs, + noverlap=fftlen/4, + window = lambda d: d*winfunc(fftlen)) + s3.set_title("Output of Synthesis Filter") + + pylab.show() + +if __name__ == "__main__": + main()