3 * Copyright 2009 Free Software Foundation, Inc.
5 * This file is part of GNU Radio
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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)
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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
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19 * the Free Software Foundation, Inc., 51 Franklin Street,
20 * Boston, MA 02110-1301, USA.
27 #include <gr_pfb_channelizer_ccf.h>
28 #include <gr_fir_ccf.h>
29 #include <gr_fir_util.h>
31 #include <gr_io_signature.h>
33 gr_pfb_channelizer_ccf_sptr gr_make_pfb_channelizer_ccf (unsigned int numchans,
34 const std::vector<float> &taps)
36 return gr_pfb_channelizer_ccf_sptr (new gr_pfb_channelizer_ccf (numchans, taps));
40 gr_pfb_channelizer_ccf::gr_pfb_channelizer_ccf (unsigned int numchans,
41 const std::vector<float> &taps)
42 : gr_sync_block ("pfb_channelizer_ccf",
43 gr_make_io_signature (numchans, numchans, sizeof(gr_complex)),
44 gr_make_io_signature (1, 1, numchans*sizeof(gr_complex))),
47 d_numchans = numchans;
48 d_filters = std::vector<gr_fir_ccf*>(d_numchans);
50 // Create an FIR filter for each channel and zero out the taps
51 std::vector<float> vtaps(0, d_numchans);
52 for(unsigned int i = 0; i < d_numchans; i++) {
53 d_filters[i] = gr_fir_util::create_gr_fir_ccf(vtaps);
56 // Now, actually set the filters' taps
59 // Create the FFT to handle the output de-spinning of the channels
60 d_fft = new gri_fft_complex (d_numchans, false);
63 gr_pfb_channelizer_ccf::~gr_pfb_channelizer_ccf ()
65 for(unsigned int i = 0; i < d_numchans; i++) {
71 gr_pfb_channelizer_ccf::set_taps (const std::vector<float> &taps)
75 unsigned int ntaps = taps.size();
76 d_taps_per_filter = (unsigned int)ceil((double)ntaps/(double)d_numchans);
78 // Create d_numchan vectors to store each channel's taps
79 d_taps.resize(d_numchans);
81 // Make a vector of the taps plus fill it out with 0's to fill
82 // each polyphase filter with exactly d_taps_per_filter
83 std::vector<float> tmp_taps;
85 while((float)(tmp_taps.size()) < d_numchans*d_taps_per_filter) {
86 tmp_taps.push_back(0.0);
89 // Partition the filter
90 for(i = 0; i < d_numchans; i++) {
91 // Each channel uses all d_taps_per_filter with 0's if not enough taps to fill out
92 d_taps[i] = std::vector<float>(d_taps_per_filter, 0);
93 for(j = 0; j < d_taps_per_filter; j++) {
94 d_taps[i][j] = tmp_taps[i + j*d_numchans]; // add taps to channels in reverse order
97 // Build a filter for each channel and add it's taps to it
98 d_filters[i]->set_taps(d_taps[i]);
101 // Set the history to ensure enough input items for each filter
102 set_history (d_taps_per_filter);
108 gr_pfb_channelizer_ccf::print_taps()
111 for(i = 0; i < d_numchans; i++) {
112 printf("filter[%d]: [", i);
113 for(j = 0; j < d_taps_per_filter; j++) {
114 printf(" %.4e", d_taps[i][j]);
122 gr_pfb_channelizer_ccf::work (int noutput_items,
123 gr_vector_const_void_star &input_items,
124 gr_vector_void_star &output_items)
126 gr_complex *in = (gr_complex *) input_items[0];
127 gr_complex *out = (gr_complex *) output_items[0];
131 return 0; // history requirements may have changed.
134 for(int i = 0; i < noutput_items; i++) {
135 // Move through filters from bottom to top
136 for(int j = d_numchans-1; j >= 0; j--) {
137 // Take in the items from the first input stream to d_numchans
138 in = (gr_complex*)input_items[d_numchans - 1 - j];
140 // Filter current input stream from bottom filter to top
141 d_fft->get_inbuf()[j] = d_filters[j]->filter(&in[i]);
144 // despin through FFT
146 memcpy(&out[d_numchans*i], d_fft->get_outbuf(), d_numchans*sizeof(gr_complex));
149 return noutput_items;