3 * Copyright 2010 Free Software Foundation, Inc.
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27 #include <gr_pfb_synthesis_filterbank_ccf.h>
29 #include <gr_io_signature.h>
33 gr_pfb_synthesis_filterbank_ccf_sptr gr_make_pfb_synthesis_filterbank_ccf
34 (unsigned int numchans, const std::vector<float> &taps)
36 return gr_pfb_synthesis_filterbank_ccf_sptr
37 (new gr_pfb_synthesis_filterbank_ccf (numchans, taps));
41 gr_pfb_synthesis_filterbank_ccf::gr_pfb_synthesis_filterbank_ccf
42 (unsigned int numchans, const std::vector<float> &taps)
43 : gr_sync_interpolator ("pfb_synthesis_filterbank_ccf",
44 gr_make_io_signature (1, numchans, sizeof(gr_complex)),
45 gr_make_io_signature (1, 1, sizeof(gr_complex)),
47 d_updated (false), d_numchans(numchans)
49 d_filters = std::vector<gri_fir_filter_with_buffer_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] = new gri_fir_filter_with_buffer_ccf(vtaps);
57 // Now, actually set the filters' taps
60 // Create the IFFT to handle the input channel rotations
61 d_fft = new gri_fft_complex (d_numchans, true);
64 gr_pfb_synthesis_filterbank_ccf::~gr_pfb_synthesis_filterbank_ccf ()
66 for(unsigned int i = 0; i < d_numchans; i++) {
72 gr_pfb_synthesis_filterbank_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+1);
109 gr_pfb_synthesis_filterbank_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_synthesis_filterbank_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];
129 int numsigs = input_items.size();
130 int ndiff = d_numchans - numsigs;
131 unsigned int nhalf = (unsigned int)ceil((float)numsigs/2.0f);
135 return 0; // history requirements may have changed.
139 for(n = 0; n < noutput_items/d_numchans; n++) {
140 // fill up the populated channels based on the
141 // number of real input streams
142 for(i = 0; i < nhalf; i++) {
143 in = (gr_complex*)input_items[i];
144 d_fft->get_inbuf()[i] = (in+i)[n];
147 // Make the ndiff channels around N/2 0
148 for(; i < nhalf+ndiff; i++) {
149 d_fft->get_inbuf()[i] = gr_complex(0,0);
152 // Finish off channels with data
153 for(; i < d_numchans; i++) {
154 in = (gr_complex*)input_items[i-ndiff];
155 d_fft->get_inbuf()[i] = (in+i)[n];
161 for(i = 0; i < d_numchans; i++) {
162 out[d_numchans-i-1] = d_filters[d_numchans-i-1]->filter(d_fft->get_outbuf()[i]);
168 return noutput_items;