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 = 2000000 # 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, 475.50, 50,
39 attenuation_dB=100, 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
47 # Create a set of signals at different frequencies
48 # freqs lists the frequencies of the signals that get stored
49 # in the list "signals", which then get summed together
51 self.add = gr.add_cc()
52 freqs = [-4070, -3050, -2030, -1010, 10, 1020, 2040, 3060, 4080]
53 for i in xrange(len(freqs)):
54 self.signals.append(gr.sig_source_c(self._fs, gr.GR_SIN_WAVE, freqs[i], 1))
55 self.connect(self.signals[i], (self.add,i))
57 self.head = gr.head(gr.sizeof_gr_complex, self._N)
59 # Construct the channelizer filter
60 self.pfb = blks2.pfb_channelizer_ccf(self._M, self._taps)
62 # Construct a vector sink for the input signal to the channelizer
63 self.snk_i = gr.vector_sink_c()
66 self.connect(self.add, self.head, self.pfb)
67 self.connect(self.add, self.snk_i)
69 # Create a vector sink for each of M output channels of the filter and connect it
71 for i in xrange(self._M):
72 self.snks.append(gr.vector_sink_c())
73 self.connect((self.pfb, i), self.snks[i])
83 print "Run time: %f" % (tend - tstart)
86 fig_in = pylab.figure(1, figsize=(16,9), facecolor="w")
87 fig1 = pylab.figure(2, figsize=(16,9), facecolor="w")
88 fig2 = pylab.figure(3, figsize=(16,9), facecolor="w")
94 winfunc = scipy.blackman
97 # Plot the input signal on its own figure
98 d = tb.snk_i.data()[Ns:Ne]
99 spin_f = fig_in.add_subplot(2, 1, 1)
101 X,freq = mlab.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs,
102 window = lambda d: d*winfunc(fftlen),
104 X_in = 10.0*scipy.log10(abs(X))
105 f_in = scipy.arange(-fs/2.0, fs/2.0, fs/float(X_in.size))
106 pin_f = spin_f.plot(f_in, X_in, "b")
107 spin_f.set_xlim([min(f_in), max(f_in)+1])
108 spin_f.set_ylim([-200.0, 50.0])
110 spin_f.set_title("Input Signal", weight="bold")
111 spin_f.set_xlabel("Frequency (Hz)")
112 spin_f.set_ylabel("Power (dBW)")
118 t_in = scipy.arange(0, Tmax, Ts)
119 x_in = scipy.array(d)
120 spin_t = fig_in.add_subplot(2, 1, 2)
121 pin_t = spin_t.plot(t_in, x_in.real, "b")
122 pin_t = spin_t.plot(t_in, x_in.imag, "r")
124 spin_t.set_xlabel("Time (s)")
125 spin_t.set_ylabel("Amplitude")
127 Ncols = int(scipy.floor(scipy.sqrt(tb._M)))
128 Nrows = int(scipy.floor(tb._M / Ncols))
129 if(tb._M % Ncols != 0):
132 # Plot each of the channels outputs. Frequencies on Figure 2 and
133 # time signals on Figure 3
134 fs_o = tb._fs / tb._M
137 for i in xrange(len(tb.snks)):
138 # remove issues with the transients at the beginning
139 # also remove some corruption at the end of the stream
140 # this is a bug, probably due to the corner cases
141 d = tb.snks[i].data()[Ns:Ne]
143 sp1_f = fig1.add_subplot(Nrows, Ncols, 1+i)
144 X,freq = mlab.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs_o,
145 window = lambda d: d*winfunc(fftlen),
147 X_o = 10.0*scipy.log10(abs(X))
148 f_o = scipy.arange(-fs_o/2.0, fs_o/2.0, fs_o/float(X_o.size))
149 p2_f = sp1_f.plot(f_o, X_o, "b")
150 sp1_f.set_xlim([min(f_o), max(f_o)+1])
151 sp1_f.set_ylim([-200.0, 50.0])
153 sp1_f.set_title(("Channel %d" % i), weight="bold")
154 sp1_f.set_xlabel("Frequency (Hz)")
155 sp1_f.set_ylabel("Power (dBW)")
158 t_o = scipy.arange(0, Tmax_o, Ts_o)
159 sp2_o = fig2.add_subplot(Nrows, Ncols, 1+i)
160 p2_o = sp2_o.plot(t_o, x_o.real, "b")
161 p2_o = sp2_o.plot(t_o, x_o.imag, "r")
162 sp2_o.set_xlim([min(t_o), max(t_o)+1])
163 sp2_o.set_ylim([-2, 2])
165 sp2_o.set_title(("Channel %d" % i), weight="bold")
166 sp2_o.set_xlabel("Time (s)")
167 sp2_o.set_ylabel("Amplitude")
172 if __name__ == "__main__":
175 except KeyboardInterrupt: