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-rwxr-xr-xgnuradio-examples/python/pfb/resampler.py95
1 files changed, 95 insertions, 0 deletions
diff --git a/gnuradio-examples/python/pfb/resampler.py b/gnuradio-examples/python/pfb/resampler.py
new file mode 100755
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+++ b/gnuradio-examples/python/pfb/resampler.py
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+#!/usr/bin/env python
+
+from gnuradio import gr, blks2
+import scipy, pylab
+
+class mytb(gr.top_block):
+ def __init__(self, fs_in, fs_out, fc, N=10000):
+ gr.top_block.__init__(self)
+
+ rerate = float(fs_out) / float(fs_in)
+ print "Resampling from %f to %f by %f " %(fs_in, fs_out, rerate)
+
+ # Creating our own taps
+ taps = gr.firdes.low_pass_2(32, 32, 0.25, 0.1, 80)
+
+ self.src = gr.sig_source_c(fs_in, gr.GR_SIN_WAVE, fc, 1)
+ #self.src = gr.noise_source_c(gr.GR_GAUSSIAN, 1)
+ self.head = gr.head(gr.sizeof_gr_complex, N)
+
+ # A resampler with our taps
+ self.resamp_0 = blks2.pfb_arb_resampler_ccf(rerate, taps,
+ flt_size=32)
+
+ # A resampler that just needs a resampling rate.
+ # Filter is created for us and designed to cover
+ # entire bandwidth of the input signal.
+ # An optional atten=XX rate can be used here to
+ # specify the out-of-band rejection (default=80).
+ self.resamp_1 = blks2.pfb_arb_resampler_ccf(rerate)
+
+ self.snk_in = gr.vector_sink_c()
+ self.snk_0 = gr.vector_sink_c()
+ self.snk_1 = gr.vector_sink_c()
+
+ self.connect(self.src, self.head, self.snk_in)
+ self.connect(self.head, self.resamp_0, self.snk_0)
+ self.connect(self.head, self.resamp_1, self.snk_1)
+
+def main():
+ fs_in = 8000
+ fs_out = 20000
+ fc = 1000
+ N = 10000
+
+ tb = mytb(fs_in, fs_out, fc, N)
+ tb.run()
+
+
+ # Plot PSD of signals
+ nfftsize = 2048
+ fig1 = pylab.figure(1, figsize=(10,10), facecolor="w")
+ sp1 = fig1.add_subplot(2,1,1)
+ sp1.psd(tb.snk_in.data(), NFFT=nfftsize,
+ noverlap=nfftsize/4, Fs = fs_in)
+ sp1.set_title(("Input Signal at f_s=%.2f kHz" % (fs_in/1000.0)))
+ sp1.set_xlim([-fs_in/2, fs_in/2])
+
+ sp2 = fig1.add_subplot(2,1,2)
+ sp2.psd(tb.snk_0.data(), NFFT=nfftsize,
+ noverlap=nfftsize/4, Fs = fs_out,
+ label="With our filter")
+ sp2.psd(tb.snk_1.data(), NFFT=nfftsize,
+ noverlap=nfftsize/4, Fs = fs_out,
+ label="With auto-generated filter")
+ sp2.set_title(("Output Signals at f_s=%.2f kHz" % (fs_out/1000.0)))
+ sp2.set_xlim([-fs_out/2, fs_out/2])
+ sp2.legend()
+
+ # Plot signals in time
+ Ts_in = 1.0/fs_in
+ Ts_out = 1.0/fs_out
+ t_in = scipy.arange(0, len(tb.snk_in.data())*Ts_in, Ts_in)
+ t_out = scipy.arange(0, len(tb.snk_0.data())*Ts_out, Ts_out)
+
+ fig2 = pylab.figure(2, figsize=(10,10), facecolor="w")
+ sp21 = fig2.add_subplot(2,1,1)
+ sp21.plot(t_in, tb.snk_in.data())
+ sp21.set_title(("Input Signal at f_s=%.2f kHz" % (fs_in/1000.0)))
+ sp21.set_xlim([t_in[100], t_in[200]])
+
+ sp22 = fig2.add_subplot(2,1,2)
+ sp22.plot(t_out, tb.snk_0.data(),
+ label="With our filter")
+ sp22.plot(t_out, tb.snk_1.data(),
+ label="With auto-generated filter")
+ sp22.set_title(("Output Signals at f_s=%.2f kHz" % (fs_out/1000.0)))
+ r = float(fs_out)/float(fs_in)
+ sp22.set_xlim([t_out[r * 100], t_out[r * 200]])
+ sp22.legend()
+
+ pylab.show()
+
+if __name__ == "__main__":
+ main()
+