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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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>
34 gr_pfb_channelizer_ccf_sptr gr_make_pfb_channelizer_ccf (unsigned int numchans,
35 const std::vector<float> &taps)
37 return gr_pfb_channelizer_ccf_sptr (new gr_pfb_channelizer_ccf (numchans, taps));
41 gr_pfb_channelizer_ccf::gr_pfb_channelizer_ccf (unsigned int numchans,
42 const std::vector<float> &taps)
43 : gr_sync_block ("pfb_channelizer_ccf",
44 gr_make_io_signature (numchans, numchans, sizeof(gr_complex)),
45 gr_make_io_signature (1, 1, numchans*sizeof(gr_complex))),
48 d_numchans = numchans;
49 d_filters = std::vector<gr_fir_ccf*>(d_numchans);
51 // Create an FIR filter for each channel and zero out the taps
52 std::vector<float> vtaps(0, d_numchans);
53 for(unsigned int i = 0; i < d_numchans; i++) {
54 d_filters[i] = gr_fir_util::create_gr_fir_ccf(vtaps);
57 // Now, actually set the filters' taps
60 // Create the FFT to handle the output de-spinning of the channels
61 d_fft = new gri_fft_complex (d_numchans, false);
64 gr_pfb_channelizer_ccf::~gr_pfb_channelizer_ccf ()
66 for(unsigned int i = 0; i < d_numchans; i++) {
72 gr_pfb_channelizer_ccf::set_taps (const std::vector<float> &taps)
76 unsigned int ntaps = taps.size();
77 d_taps_per_filter = (unsigned int)ceil((double)ntaps/(double)d_numchans);
79 // Create d_numchan vectors to store each channel's taps
80 d_taps.resize(d_numchans);
82 // Make a vector of the taps plus fill it out with 0's to fill
83 // each polyphase filter with exactly d_taps_per_filter
84 std::vector<float> tmp_taps;
86 while((float)(tmp_taps.size()) < d_numchans*d_taps_per_filter) {
87 tmp_taps.push_back(0.0);
90 // Partition the filter
91 for(i = 0; i < d_numchans; i++) {
92 // Each channel uses all d_taps_per_filter with 0's if not enough taps to fill out
93 d_taps[i] = std::vector<float>(d_taps_per_filter, 0);
94 for(j = 0; j < d_taps_per_filter; j++) {
95 d_taps[i][j] = tmp_taps[i + j*d_numchans]; // add taps to channels in reverse order
98 // Build a filter for each channel and add it's taps to it
99 d_filters[i]->set_taps(d_taps[i]);
102 // Set the history to ensure enough input items for each filter
103 set_history (d_taps_per_filter);
109 gr_pfb_channelizer_ccf::print_taps()
112 for(i = 0; i < d_numchans; i++) {
113 printf("filter[%d]: [", i);
114 for(j = 0; j < d_taps_per_filter; j++) {
115 printf(" %.4e", d_taps[i][j]);
123 gr_pfb_channelizer_ccf::work (int noutput_items,
124 gr_vector_const_void_star &input_items,
125 gr_vector_void_star &output_items)
127 gr_complex *in = (gr_complex *) input_items[0];
128 gr_complex *out = (gr_complex *) output_items[0];
132 return 0; // history requirements may have changed.
135 for(int i = 0; i < noutput_items; i++) {
136 // Move through filters from bottom to top
137 for(int j = d_numchans-1; j >= 0; j--) {
138 // Take in the items from the first input stream to d_numchans
139 in = (gr_complex*)input_items[d_numchans - 1 - j];
141 // Filter current input stream from bottom filter to top
142 d_fft->get_inbuf()[j] = d_filters[j]->filter(&in[i]);
145 // despin through FFT
147 memcpy(&out[d_numchans*i], d_fft->get_outbuf(), d_numchans*sizeof(gr_complex));
150 return noutput_items;