--- /dev/null
+/* -*- c++ -*- */
+/*
+ * Copyright 2009,2010 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gr_pfb_channelizer_ccf.h>
+#include <gr_fir_ccf.h>
+#include <gr_fir_util.h>
+#include <gri_fft.h>
+#include <gr_io_signature.h>
+#include <cstdio>
+#include <cstring>
+
+gr_pfb_channelizer_ccf_sptr gr_make_pfb_channelizer_ccf (unsigned int numchans,
+ const std::vector<float> &taps,
+ float oversample_rate)
+{
+ return gr_pfb_channelizer_ccf_sptr (new gr_pfb_channelizer_ccf (numchans, taps,
+ oversample_rate));
+}
+
+
+gr_pfb_channelizer_ccf::gr_pfb_channelizer_ccf (unsigned int numchans,
+ const std::vector<float> &taps,
+ float oversample_rate)
+ : gr_block ("pfb_channelizer_ccf",
+ gr_make_io_signature (numchans, numchans, sizeof(gr_complex)),
+ gr_make_io_signature (1, 1, numchans*sizeof(gr_complex))),
+ d_updated (false), d_numchans(numchans), d_oversample_rate(oversample_rate)
+{
+ // The over sampling rate must be rationally related to the number of channels
+ // in that it must be N/i for i in [1,N], which gives an outputsample rate
+ // of [fs/N, fs] where fs is the input sample rate.
+ // This tests the specified input sample rate to see if it conforms to this
+ // requirement within a few significant figures.
+ double intp = 0;
+ double x = (10000.0*rint(numchans / oversample_rate)) / 10000.0;
+ double fltp = modf(numchans / oversample_rate, &intp);
+ if(fltp != 0.0)
+ throw std::invalid_argument("gr_pfb_channelizer: oversample rate must be N/i for i in [1, N]");
+
+ d_filters = std::vector<gr_fir_ccf*>(d_numchans);
+
+ // Create an FIR filter for each channel and zero out the taps
+ std::vector<float> vtaps(0, d_numchans);
+ for(unsigned int i = 0; i < d_numchans; i++) {
+ d_filters[i] = gr_fir_util::create_gr_fir_ccf(vtaps);
+ }
+
+ // Now, actually set the filters' taps
+ set_taps(taps);
+
+ // Create the FFT to handle the output de-spinning of the channels
+ d_fft = new gri_fft_complex (d_numchans, false);
+
+ // Although the filters change, we use this look up table
+ // to set the index of the FFT input buffer, which equivalently
+ // performs the FFT shift operation on every other turn.
+ d_rate_ratio = (int)rintf(d_numchans / d_oversample_rate);
+ d_idxlut = new int[d_numchans];
+ for(unsigned int i = 0; i < d_numchans; i++) {
+ d_idxlut[i] = d_numchans - ((i + d_rate_ratio) % d_numchans) - 1;
+ }
+
+ // Calculate the number of filtering rounds to do to evenly
+ // align the input vectors with the output channels
+ d_output_multiple = 1;
+ while((d_output_multiple * d_rate_ratio) % d_numchans != 0)
+ d_output_multiple++;
+ set_output_multiple(d_output_multiple);
+}
+
+gr_pfb_channelizer_ccf::~gr_pfb_channelizer_ccf ()
+{
+ delete [] d_idxlut;
+
+ for(unsigned int i = 0; i < d_numchans; i++) {
+ delete d_filters[i];
+ }
+}
+
+void
+gr_pfb_channelizer_ccf::set_taps (const std::vector<float> &taps)
+{
+ unsigned int i,j;
+
+ unsigned int ntaps = taps.size();
+ d_taps_per_filter = (unsigned int)ceil((double)ntaps/(double)d_numchans);
+
+ // Create d_numchan vectors to store each channel's taps
+ d_taps.resize(d_numchans);
+
+ // Make a vector of the taps plus fill it out with 0's to fill
+ // each polyphase filter with exactly d_taps_per_filter
+ std::vector<float> tmp_taps;
+ tmp_taps = taps;
+ while((float)(tmp_taps.size()) < d_numchans*d_taps_per_filter) {
+ tmp_taps.push_back(0.0);
+ }
+
+ // Partition the filter
+ for(i = 0; i < d_numchans; i++) {
+ // Each channel uses all d_taps_per_filter with 0's if not enough taps to fill out
+ d_taps[i] = std::vector<float>(d_taps_per_filter, 0);
+ for(j = 0; j < d_taps_per_filter; j++) {
+ d_taps[i][j] = tmp_taps[i + j*d_numchans]; // add taps to channels in reverse order
+ }
+
+ // Build a filter for each channel and add it's taps to it
+ d_filters[i]->set_taps(d_taps[i]);
+ }
+
+ // Set the history to ensure enough input items for each filter
+ set_history (d_taps_per_filter+1);
+
+ d_updated = true;
+}
+
+void
+gr_pfb_channelizer_ccf::print_taps()
+{
+ unsigned int i, j;
+ for(i = 0; i < d_numchans; i++) {
+ printf("filter[%d]: [", i);
+ for(j = 0; j < d_taps_per_filter; j++) {
+ printf(" %.4e", d_taps[i][j]);
+ }
+ printf("]\n\n");
+ }
+}
+
+
+int
+gr_pfb_channelizer_ccf::general_work (int noutput_items,
+ gr_vector_int &ninput_items,
+ gr_vector_const_void_star &input_items,
+ gr_vector_void_star &output_items)
+{
+ gr_complex *in = (gr_complex *) input_items[0];
+ gr_complex *out = (gr_complex *) output_items[0];
+
+ if (d_updated) {
+ d_updated = false;
+ return 0; // history requirements may have changed.
+ }
+
+ int n=1, i=-1, j=0, last;
+ int toconsume = (int)rintf(noutput_items/d_oversample_rate);
+ while(n <= toconsume) {
+ j = 0;
+ i = (i + d_rate_ratio) % d_numchans;
+ last = i;
+ while(i >= 0) {
+ in = (gr_complex*)input_items[j];
+ d_fft->get_inbuf()[d_idxlut[j]] = d_filters[i]->filter(&in[n]);
+ j++;
+ i--;
+ }
+
+ i = d_numchans-1;
+ while(i > last) {
+ in = (gr_complex*)input_items[j];
+ d_fft->get_inbuf()[d_idxlut[j]] = d_filters[i]->filter(&in[n-1]);
+ j++;
+ i--;
+ }
+
+ n += (i+d_rate_ratio) >= (int)d_numchans;
+
+ // despin through FFT
+ d_fft->execute();
+ memcpy(out, d_fft->get_outbuf(), d_numchans*sizeof(gr_complex));
+ out += d_numchans;
+ }
+
+ consume_each(toconsume);
+ return noutput_items;
+}
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