content: #!/usr/bin/env python
  #
  # Copyright 2009 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 sys, 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
      from pylab import mlab
  except ImportError:
      print "Error: Program requires matplotlib (see: matplotlib.sourceforge.net)."
      sys.exit(1)
  
  class pfb_top_block(gr.top_block):
      def __init__(self):
          gr.top_block.__init__(self)
  
          self._N = 100000        # number of samples to use
          self._fs = 2000         # initial sampling rate
          self._interp = 5        # Interpolation rate for PFB interpolator
          self._ainterp = 5.5       # Resampling rate for the PFB arbitrary resampler
  
          # Frequencies of the signals we construct
          freq1 = 100
          freq2 = 200
  
          # Create a set of taps for the PFB interpolator
          # This is based on the post-interpolation sample rate
          self._taps = gr.firdes.low_pass_2(self._interp, self._interp*self._fs, freq2+50, 50,
                                            attenuation_dB=120, window=gr.firdes.WIN_BLACKMAN_hARRIS)
  
          # Create a set of taps for the PFB arbitrary resampler
          # The filter size is the number of filters in the filterbank; 32 will give very low side-lobes,
          # and larger numbers will reduce these even farther
          # The taps in this filter are based on a sampling rate of the filter size since it acts
          # internally as an interpolator.
          flt_size = 32
          self._taps2 = gr.firdes.low_pass_2(flt_size, flt_size*self._fs, freq2+50, 150,
                                             attenuation_dB=120, window=gr.firdes.WIN_BLACKMAN_hARRIS)
  
          # Calculate the number of taps per channel for our own information
          tpc = scipy.ceil(float(len(self._taps)) /  float(self._interp))
          print "Number of taps:     ", len(self._taps)
          print "Number of filters:  ", self._interp
          print "Taps per channel:   ", tpc
  
          # Create a couple of signals at different frequencies
          self.signal1 = gr.sig_source_c(self._fs, gr.GR_SIN_WAVE, freq1, 0.5)
          self.signal2 = gr.sig_source_c(self._fs, gr.GR_SIN_WAVE, freq2, 0.5)
          self.signal = gr.add_cc()
  
          self.head = gr.head(gr.sizeof_gr_complex, self._N)
  
          # Construct the PFB interpolator filter
          self.pfb = blks2.pfb_interpolator_ccf(self._interp, self._taps)
  
          # Construct the PFB arbitrary resampler filter
          self.pfb_ar = blks2.pfb_arb_resampler_ccf(self._ainterp, self._taps2, flt_size)
          self.snk_i = gr.vector_sink_c()
  
          #self.pfb_ar.pfb.print_taps()
          #self.pfb.pfb.print_taps()
  
          # Connect the blocks
          self.connect(self.signal1, self.head, (self.signal,0))
          self.connect(self.signal2, (self.signal,1))
          self.connect(self.signal, self.pfb)
          self.connect(self.signal, self.pfb_ar)
          self.connect(self.signal, self.snk_i)
  
          # Create the sink for the interpolated signals
          self.snk1 = gr.vector_sink_c()
          self.snk2 = gr.vector_sink_c()
          self.connect(self.pfb, self.snk1)
          self.connect(self.pfb_ar, self.snk2)
  
  
  def main():
      tb = pfb_top_block()
  
      tstart = time.time()
      tb.run()
      tend = time.time()
      print "Run time: %f" % (tend - tstart)
  
  
      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 = 10000
  
          fftlen = 8192
          winfunc = scipy.blackman
  
          # Plot input signal
          fs = tb._fs
  
          d = tb.snk_i.data()[Ns:Ns+Ne]
          sp1_f = fig1.add_subplot(2, 1, 1)
  
          X,freq = mlab.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs,
                            window = lambda d: d*winfunc(fftlen),
                            scale_by_freq=True)
          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([-200.0, 50.0])
  
  
          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([-2.5, 2.5])
  
          sp1_t.set_title("Input Signal", weight="bold")
          sp1_t.set_xlabel("Time (s)")
          sp1_t.set_ylabel("Amplitude")
  
  
          # Plot output of PFB interpolator
          fs_int = tb._fs*tb._interp
  
          sp2_f = fig2.add_subplot(2, 1, 1)
          d = tb.snk1.data()[Ns:Ns+(tb._interp*Ne)]
          X,freq = mlab.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs,
                            window = lambda d: d*winfunc(fftlen),
                            scale_by_freq=True)
          X_o = 10.0*scipy.log10(abs(fftpack.fftshift(X)))
          f_o = scipy.arange(-fs_int/2.0, fs_int/2.0, fs_int/float(X_o.size))
          p2_f = sp2_f.plot(f_o, X_o, "b")
          sp2_f.set_xlim([min(f_o), max(f_o)+1])
          sp2_f.set_ylim([-200.0, 50.0])
  
          sp2_f.set_title("Output Signal from PFB Interpolator", weight="bold")
          sp2_f.set_xlabel("Frequency (Hz)")
          sp2_f.set_ylabel("Power (dBW)")
  
          Ts_int = 1.0/fs_int
          Tmax = len(d)*Ts_int
  
          t_o = scipy.arange(0, Tmax, Ts_int)
          x_o1 = scipy.array(d)
          sp2_t = fig2.add_subplot(2, 1, 2)
          p2_t = sp2_t.plot(t_o, x_o1.real, "b-o")
          #p2_t = sp2_t.plot(t_o, x_o.imag, "r-o")
          sp2_t.set_ylim([-2.5, 2.5])
  
          sp2_t.set_title("Output Signal from PFB Interpolator", weight="bold")
          sp2_t.set_xlabel("Time (s)")
          sp2_t.set_ylabel("Amplitude")
  
  
          # Plot output of PFB arbitrary resampler
          fs_aint = tb._fs * tb._ainterp
  
          sp3_f = fig3.add_subplot(2, 1, 1)
          d = tb.snk2.data()[Ns:Ns+(tb._interp*Ne)]
          X,freq = mlab.psd(d, NFFT=fftlen, noverlap=fftlen/4, Fs=fs,
                            window = lambda d: d*winfunc(fftlen),
                            scale_by_freq=True)
          X_o = 10.0*scipy.log10(abs(fftpack.fftshift(X)))
          f_o = scipy.arange(-fs_aint/2.0, fs_aint/2.0, fs_aint/float(X_o.size))
          p3_f = sp3_f.plot(f_o, X_o, "b")
          sp3_f.set_xlim([min(f_o), max(f_o)+1])
          sp3_f.set_ylim([-200.0, 50.0])
  
          sp3_f.set_title("Output Signal from PFB Arbitrary Resampler", weight="bold")
          sp3_f.set_xlabel("Frequency (Hz)")
          sp3_f.set_ylabel("Power (dBW)")
  
          Ts_aint = 1.0/fs_aint
          Tmax = len(d)*Ts_aint
  
          t_o = scipy.arange(0, Tmax, Ts_aint)
          x_o2 = scipy.array(d)
          sp3_f = fig3.add_subplot(2, 1, 2)
          p3_f = sp3_f.plot(t_o, x_o2.real, "b-o")
          p3_f = sp3_f.plot(t_o, x_o1.real, "m-o")
          #p3_f = sp3_f.plot(t_o, x_o2.imag, "r-o")
          sp3_f.set_ylim([-2.5, 2.5])
  
          sp3_f.set_title("Output Signal from PFB Arbitrary Resampler", weight="bold")
          sp3_f.set_xlabel("Time (s)")
          sp3_f.set_ylabel("Amplitude")
  
          pylab.show()
  
  
  if __name__ == "__main__":
      try:
          main()
      except KeyboardInterrupt:
          pass
  
  