Merge branch 'gr_filter'

1 files changed, 226 insertions, 0 deletions

diff --git a/gr-filter/examples/fmtest.py b/gr-filter/examples/fmtest.py
new file mode 100755
index 000000000..9b02526d9
--- /dev/null
+++ b/gr-filter/examples/fmtest.py
@@ -0,0 +1,226 @@
+#!/usr/bin/env python
+#
+# Copyright 2009,2012 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
+from gnuradio import filter
+import sys, math, time
+
+try:
+    import scipy
+    from scipy import fftpack
+except ImportError:
+    print "Error: Program requires scipy (see: www.scipy.org)."
+    sys.exit(1)
+
+try:
+    import pylab
+except ImportError:
+    print "Error: Program requires matplotlib (see: matplotlib.sourceforge.net)."
+    sys.exit(1)
+
+
+class fmtx(gr.hier_block2):
+    def __init__(self, lo_freq, audio_rate, if_rate):
+
+        gr.hier_block2.__init__(self, "build_fm",
+                                gr.io_signature(1, 1, gr.sizeof_float),
+                                gr.io_signature(1, 1, gr.sizeof_gr_complex))
+
+        fmtx = blks2.nbfm_tx (audio_rate, if_rate, max_dev=5e3, tau=75e-6)
+
+        # Local oscillator
+        lo = gr.sig_source_c (if_rate,        # sample rate
+                              gr.GR_SIN_WAVE, # waveform type
+                              lo_freq,        #frequency
+                              1.0,            # amplitude
+                              0)              # DC Offset
+        mixer = gr.multiply_cc ()
+
+        self.connect (self, fmtx, (mixer, 0))
+        self.connect (lo, (mixer, 1))
+        self.connect (mixer, self)
+
+class fmtest(gr.top_block):
+    def __init__(self):
+        gr.top_block.__init__(self)
+
+        self._nsamples = 1000000
+        self._audio_rate = 8000
+
+        # Set up N channels with their own baseband and IF frequencies
+        self._N = 5
+        chspacing = 16000
+        freq = [10, 20, 30, 40, 50]
+        f_lo = [0, 1*chspacing, -1*chspacing, 2*chspacing, -2*chspacing]
+
+        self._if_rate = 4*self._N*self._audio_rate
+
+        # Create a signal source and frequency modulate it
+        self.sum = gr.add_cc ()
+        for n in xrange(self._N):
+            sig = gr.sig_source_f(self._audio_rate, gr.GR_SIN_WAVE, freq[n], 0.5)
+            fm = fmtx(f_lo[n], self._audio_rate, self._if_rate)
+            self.connect(sig, fm)
+            self.connect(fm, (self.sum, n))
+
+        self.head = gr.head(gr.sizeof_gr_complex, self._nsamples)
+        self.snk_tx = gr.vector_sink_c()
+        self.channel = blks2.channel_model(0.1)
+
+        self.connect(self.sum, self.head, self.channel, self.snk_tx)
+
+
+        # Design the channlizer
+        self._M = 10
+        bw = chspacing/2.0
+        t_bw = chspacing/10.0
+        self._chan_rate = self._if_rate / self._M
+        self._taps = filter.firdes.low_pass_2(1, self._if_rate, bw, t_bw,
+                                              attenuation_dB=100,
+                                              window=filter.firdes.WIN_BLACKMAN_hARRIS)
+        tpc = math.ceil(float(len(self._taps)) /  float(self._M))
+
+        print "Number of taps:     ", len(self._taps)
+        print "Number of channels: ", self._M
+        print "Taps per channel:   ", tpc
+
+        self.pfb = filter.pfb.channelizer_ccf(self._M, self._taps)
+
+        self.connect(self.channel, self.pfb)
+
+        # Create a file sink for each of M output channels of the filter and connect it
+        self.fmdet = list()
+        self.squelch = list()
+        self.snks = list()
+        for i in xrange(self._M):
+            self.fmdet.append(blks2.nbfm_rx(self._audio_rate, self._chan_rate))
+            self.squelch.append(blks2.standard_squelch(self._audio_rate*10))
+            self.snks.append(gr.vector_sink_f())
+            self.connect((self.pfb, i), self.fmdet[i], self.squelch[i], self.snks[i])
+
+    def num_tx_channels(self):
+        return self._N
+
+    def num_rx_channels(self):
+        return self._M
+
+def main():
+
+    fm = fmtest()
+
+    tstart = time.time()
+    fm.run()
+    tend = time.time()
+
+    if 1:
+        fig1 = pylab.figure(1, figsize=(12,10), facecolor="w")
+        fig2 = pylab.figure(2, figsize=(12,10), facecolor="w")
+        fig3 = pylab.figure(3, figsize=(12,10), facecolor="w")
+
+        Ns = 10000
+        Ne = 100000
+
+        fftlen = 8192
+        winfunc = scipy.blackman
+
+        # Plot transmitted signal
+        fs = fm._if_rate
+
+        d = fm.snk_tx.data()[Ns:Ns+Ne]
+        sp1_f = fig1.add_subplot(2, 1, 1)
+
+        X,freq = sp1_f.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs,
+                           window = lambda d: d*winfunc(fftlen),
+                           visible=False)
+        X_in = 10.0*scipy.log10(abs(fftpack.fftshift(X)))
+        f_in = scipy.arange(-fs/2.0, fs/2.0, fs/float(X_in.size))
+        p1_f = sp1_f.plot(f_in, X_in, "b")
+        sp1_f.set_xlim([min(f_in), max(f_in)+1])
+        sp1_f.set_ylim([-120.0, 20.0])
+
+        sp1_f.set_title("Input Signal", weight="bold")
+        sp1_f.set_xlabel("Frequency (Hz)")
+        sp1_f.set_ylabel("Power (dBW)")
+
+        Ts = 1.0/fs
+        Tmax = len(d)*Ts
+
+        t_in = scipy.arange(0, Tmax, Ts)
+        x_in = scipy.array(d)
+        sp1_t = fig1.add_subplot(2, 1, 2)
+        p1_t = sp1_t.plot(t_in, x_in.real, "b-o")
+        #p1_t = sp1_t.plot(t_in, x_in.imag, "r-o")
+        sp1_t.set_ylim([-5, 5])
+
+        # Set up the number of rows and columns for plotting the subfigures
+        Ncols = int(scipy.floor(scipy.sqrt(fm.num_rx_channels())))
+        Nrows = int(scipy.floor(fm.num_rx_channels() / Ncols))
+        if(fm.num_rx_channels() % Ncols != 0):
+            Nrows += 1
+
+        # Plot each of the channels outputs. Frequencies on Figure 2 and
+        # time signals on Figure 3
+        fs_o = fm._audio_rate
+        for i in xrange(len(fm.snks)):
+            # remove issues with the transients at the beginning
+            # also remove some corruption at the end of the stream
+            #    this is a bug, probably due to the corner cases
+            d = fm.snks[i].data()[Ns:Ne]
+
+            sp2_f = fig2.add_subplot(Nrows, Ncols, 1+i)
+            X,freq = sp2_f.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs_o,
+                               window = lambda d: d*winfunc(fftlen),
+                               visible=False)
+            #X_o = 10.0*scipy.log10(abs(fftpack.fftshift(X)))
+            X_o = 10.0*scipy.log10(abs(X))
+            #f_o = scipy.arange(-fs_o/2.0, fs_o/2.0, fs_o/float(X_o.size))
+            f_o = scipy.arange(0, fs_o/2.0, fs_o/2.0/float(X_o.size))
+            p2_f = sp2_f.plot(f_o, X_o, "b")
+            sp2_f.set_xlim([min(f_o), max(f_o)+0.1])
+            sp2_f.set_ylim([-120.0, 20.0])
+            sp2_f.grid(True)
+
+            sp2_f.set_title(("Channel %d" % i), weight="bold")
+            sp2_f.set_xlabel("Frequency (kHz)")
+            sp2_f.set_ylabel("Power (dBW)")
+
+
+            Ts = 1.0/fs_o
+            Tmax = len(d)*Ts
+            t_o = scipy.arange(0, Tmax, Ts)
+
+            x_t = scipy.array(d)
+            sp2_t = fig3.add_subplot(Nrows, Ncols, 1+i)
+            p2_t = sp2_t.plot(t_o, x_t.real, "b")
+            p2_t = sp2_t.plot(t_o, x_t.imag, "r")
+            sp2_t.set_xlim([min(t_o), max(t_o)+1])
+            sp2_t.set_ylim([-1, 1])
+
+            sp2_t.set_xlabel("Time (s)")
+            sp2_t.set_ylabel("Amplitude")
+
+
+        pylab.show()
+
+
+if __name__ == "__main__":
+    main()