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, optfir
25 class pfb_decimator_ccf(gr.hier_block2):
27 Make a Polyphase Filter decimator (complex in, complex out, floating-point taps)
29 This simplifies the interface by allowing a single input stream to connect to this block.
30 It will then output a stream that is the decimated output stream.
32 def __init__(self, decim, taps=None, channel=0, atten=100):
33 gr.hier_block2.__init__(self, "pfb_decimator_ccf",
34 gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
35 gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature
38 self._channel = channel
43 # Create a filter that covers the full bandwidth of the input signal
50 self._taps = optfir.low_pass(1, self._decim, bw, bw+tb, ripple, atten)
55 print("Warning: set ripple to %.4f dB. If this is a problem, adjust the attenuation or create your own filter taps." % (ripple))
57 self.s2ss = gr.stream_to_streams(gr.sizeof_gr_complex, self._decim)
58 self.pfb = gr.pfb_decimator_ccf(self._decim, self._taps, self._channel)
60 self.connect(self, self.s2ss)
62 for i in xrange(self._decim):
63 self.connect((self.s2ss,i), (self.pfb,i))
65 self.connect(self.pfb, self)