3 # Copyright 2009 Free Software Foundation, Inc.
5 # This file is part of GNU Radio
7 # GNU Radio is free software; you can redistribute it and/or modify
8 # it under the terms of the GNU General Public License as published by
9 # the Free Software Foundation; either version 3, or (at your option)
12 # GNU Radio is distributed in the hope that it will be useful,
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 # GNU General Public License for more details.
17 # You should have received a copy of the GNU General Public License
18 # along with GNU Radio; see the file COPYING. If not, write to
19 # the Free Software Foundation, Inc., 51 Franklin Street,
20 # Boston, MA 02110-1301, USA.
23 from gnuradio import gr, blks2
26 from scipy import fftpack
27 from pylab import mlab
29 class pfb_top_block(gr.top_block):
31 gr.top_block.__init__(self)
33 self._N = 200000 # number of samples to use
34 self._fs = 9000 # initial sampling rate
35 self._M = 9 # Number of channels to channelize
37 # Create a set of taps for the PFB channelizer
38 self._taps = gr.firdes.low_pass_2(1, self._fs, 500, 20,
39 attenuation_dB=10, window=gr.firdes.WIN_BLACKMAN_hARRIS)
41 # Calculate the number of taps per channel for our own information
42 tpc = scipy.ceil(float(len(self._taps)) / float(self._M))
43 print "Number of taps: ", len(self._taps)
44 print "Number of channels: ", self._M
45 print "Taps per channel: ", tpc
49 self.vco_input = gr.sig_source_f(self._fs, gr.GR_SIN_WAVE, 0.25, 110)
52 data = scipy.arange(0, amp, amp/float(self._N))
53 self.vco_input = gr.vector_source_f(data, False)
55 # Build a VCO controlled by either the sinusoid or single chirp tone
56 # Then convert this to a complex signal
57 self.vco = gr.vco_f(self._fs, 225, 1)
58 self.f2c = gr.float_to_complex()
60 self.head = gr.head(gr.sizeof_gr_complex, self._N)
62 # Construct the channelizer filter
63 self.pfb = blks2.pfb_channelizer_ccf(self._M, self._taps)
65 # Construct a vector sink for the input signal to the channelizer
66 self.snk_i = gr.vector_sink_c()
69 self.connect(self.vco_input, self.vco, self.f2c)
70 self.connect(self.f2c, self.head, self.pfb)
71 self.connect(self.f2c, self.snk_i)
73 # Create a vector sink for each of M output channels of the filter and connect it
75 for i in xrange(self._M):
76 self.snks.append(gr.vector_sink_c())
77 self.connect((self.pfb, i), self.snks[i])
87 print "Run time: %f" % (tend - tstart)
90 fig_in = pylab.figure(1, figsize=(16,9), facecolor="w")
91 fig1 = pylab.figure(2, figsize=(16,9), facecolor="w")
92 fig2 = pylab.figure(3, figsize=(16,9), facecolor="w")
93 fig3 = pylab.figure(4, figsize=(16,9), facecolor="w")
99 winfunc = scipy.blackman
102 # Plot the input signal on its own figure
103 d = tb.snk_i.data()[Ns:Ne]
104 spin_f = fig_in.add_subplot(2, 1, 1)
106 X,freq = mlab.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs,
107 window = lambda d: d*winfunc(fftlen),
109 X_in = 10.0*scipy.log10(abs(fftpack.fftshift(X)))
110 f_in = scipy.arange(-fs/2.0, fs/2.0, fs/float(X_in.size))
111 pin_f = spin_f.plot(f_in, X_in, "b")
112 spin_f.set_xlim([min(f_in), max(f_in)+1])
113 spin_f.set_ylim([-200.0, 50.0])
115 spin_f.set_title("Input Signal", weight="bold")
116 spin_f.set_xlabel("Frequency (Hz)")
117 spin_f.set_ylabel("Power (dBW)")
123 t_in = scipy.arange(0, Tmax, Ts)
124 x_in = scipy.array(d)
125 spin_t = fig_in.add_subplot(2, 1, 2)
126 pin_t = spin_t.plot(t_in, x_in.real, "b")
127 pin_t = spin_t.plot(t_in, x_in.imag, "r")
129 spin_t.set_xlabel("Time (s)")
130 spin_t.set_ylabel("Amplitude")
132 Ncols = int(scipy.floor(scipy.sqrt(tb._M)))
133 Nrows = int(scipy.floor(tb._M / Ncols))
134 if(tb._M % Ncols != 0):
137 # Plot each of the channels outputs. Frequencies on Figure 2 and
138 # time signals on Figure 3
139 fs_o = tb._fs / tb._M
142 for i in xrange(len(tb.snks)):
143 # remove issues with the transients at the beginning
144 # also remove some corruption at the end of the stream
145 # this is a bug, probably due to the corner cases
146 d = tb.snks[i].data()[Ns:Ne]
148 sp1_f = fig1.add_subplot(Nrows, Ncols, 1+i)
149 X,freq = mlab.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs_o,
150 window = lambda d: d*winfunc(fftlen),
152 X_o = 10.0*scipy.log10(abs(X))
154 p2_f = sp1_f.plot(f_o, X_o, "b")
155 sp1_f.set_xlim([min(f_o), max(f_o)+1])
156 sp1_f.set_ylim([-200.0, 50.0])
158 sp1_f.set_title(("Channel %d" % i), weight="bold")
159 sp1_f.set_xlabel("Frequency (Hz)")
160 sp1_f.set_ylabel("Power (dBW)")
163 t_o = scipy.arange(0, Tmax_o, Ts_o)
164 sp2_o = fig2.add_subplot(Nrows, Ncols, 1+i)
165 p2_o = sp2_o.plot(t_o, x_o.real, "b")
166 p2_o = sp2_o.plot(t_o, x_o.imag, "r")
167 sp2_o.set_xlim([min(t_o), max(t_o)+1])
168 sp2_o.set_ylim([-2, 2])
170 sp2_o.set_title(("Channel %d" % i), weight="bold")
171 sp2_o.set_xlabel("Time (s)")
172 sp2_o.set_ylabel("Amplitude")
175 sp3 = fig3.add_subplot(1,1,1)
176 p3 = sp3.plot(t_o, x_o.real)
177 sp3.set_xlim([min(t_o), max(t_o)+1])
178 sp3.set_ylim([-2, 2])
180 sp3.set_title("All Channels")
181 sp3.set_xlabel("Time (s)")
182 sp3.set_ylabel("Amplitude")
187 if __name__ == "__main__":
190 except KeyboardInterrupt: