3 * Copyright 2004,2007 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.
27 #include <gr_fft_vcc.h>
28 #include <gr_io_signature.h>
33 gr_make_fft_vcc (int fft_size, bool forward,const std::vector<float> window, bool shift)
35 return gr_fft_vcc_sptr (new gr_fft_vcc (fft_size, forward, window, shift));
38 gr_fft_vcc::gr_fft_vcc (int fft_size, bool forward, const std::vector<float> window, bool shift)
39 : gr_sync_block ("fft_vcc",
40 gr_make_io_signature (1, 1, fft_size * sizeof (gr_complex)),
41 gr_make_io_signature (1, 1, fft_size * sizeof (gr_complex))),
42 d_fft_size(fft_size), d_forward(forward), d_shift(shift)
44 d_fft = new gri_fft_complex (d_fft_size, forward);
50 gr_fft_vcc::~gr_fft_vcc ()
56 gr_fft_vcc::work (int noutput_items,
57 gr_vector_const_void_star &input_items,
58 gr_vector_void_star &output_items)
60 const gr_complex *in = (const gr_complex *) input_items[0];
61 gr_complex *out = (gr_complex *) output_items[0];
63 unsigned int input_data_size = input_signature()->sizeof_stream_item (0);
64 unsigned int output_data_size = output_signature()->sizeof_stream_item (0);
68 while (count++ < noutput_items){
70 // copy input into optimally aligned buffer
73 gr_complex *dst = d_fft->get_inbuf();
74 for (unsigned int i = 0; i < d_fft_size; i++) // apply window
75 dst[i] = in[i] * d_window[i];
78 if(!d_forward && d_shift) { // apply an ifft shift on the data
79 gr_complex *dst = d_fft->get_inbuf();
80 unsigned int len = (unsigned int)(floor(d_fft_size/2.0)); // half length of complex array
81 memcpy(&dst[0], &in[len], sizeof(gr_complex)*(d_fft_size - len));
82 memcpy(&dst[d_fft_size - len], &in[0], sizeof(gr_complex)*len);
85 memcpy (d_fft->get_inbuf(), in, input_data_size);
92 // copy result to our output
93 if(d_forward && d_shift) { // apply a fft shift on the data
94 unsigned int len = (unsigned int)(ceil(d_fft_size/2.0));
95 memcpy(&out[0], &d_fft->get_outbuf()[len], sizeof(gr_complex)*(d_fft_size - len));
96 memcpy(&out[d_fft_size - len], &d_fft->get_outbuf()[0], sizeof(gr_complex)*len);
99 memcpy (out, d_fft->get_outbuf (), output_data_size);
106 return noutput_items;
110 gr_fft_vcc::set_window(const std::vector<float> window)
112 if(window.size()==0 || window.size()==d_fft_size) {
123 for(i=0; i < ceil(d_occupied_carriers/2.0); i++) {
124 unsigned int k=ceil(d_occupied_carriers/2.0);
125 out[i] = gr_complex(-1+2*in[i+k],0);
127 for(; i < d_vlen - ceil(d_occupied_carriers/2.0); i++) {
128 out[i]=gr_complex(0,0);
130 for(unsigned int j=0;i<d_vlen;i++,j++) {
131 out[i]= gr_complex((-1+2*in[j]),0);