3 * Copyright 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 2, 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_ofdm_bpsk_mapper.h>
28 #include <gr_io_signature.h>
31 gr_ofdm_bpsk_mapper_sptr
32 gr_make_ofdm_bpsk_mapper (unsigned int msgq_limit,
33 unsigned int occupied_carriers, unsigned int fft_length,
34 const std::vector<gr_complex> &known_symbol1,
35 const std::vector<gr_complex> &known_symbol2)
37 return gr_ofdm_bpsk_mapper_sptr (new gr_ofdm_bpsk_mapper (msgq_limit, occupied_carriers, fft_length,
38 known_symbol1, known_symbol2));
41 // Consumes 1 packet and produces as many OFDM symbols of fft_length to hold the full packet
42 gr_ofdm_bpsk_mapper::gr_ofdm_bpsk_mapper (unsigned int msgq_limit,
43 unsigned int occupied_carriers, unsigned int fft_length,
44 const std::vector<gr_complex> &known_symbol1,
45 const std::vector<gr_complex> &known_symbol2)
46 : gr_sync_block ("ofdm_bpsk_mapper",
47 gr_make_io_signature (0, 0, 0),
48 gr_make_io_signature2 (1, 2, sizeof(gr_complex)*fft_length, sizeof(char))),
49 d_msgq(gr_make_msg_queue(msgq_limit)), d_msg_offset(0), d_eof(false),
50 d_occupied_carriers(occupied_carriers),
51 d_fft_length(fft_length),
54 d_known_symbol1(known_symbol1),
55 d_known_symbol2(known_symbol2)
57 assert(d_occupied_carriers <= d_fft_length);
58 assert(d_occupied_carriers == d_known_symbol1.size());
59 assert(d_occupied_carriers == d_known_symbol2.size());
62 gr_ofdm_bpsk_mapper::~gr_ofdm_bpsk_mapper(void)
69 return (float)(-1 + 2*r);
73 gr_ofdm_bpsk_mapper::work(int noutput_items,
74 gr_vector_const_void_star &input_items,
75 gr_vector_void_star &output_items)
77 gr_complex *out = (gr_complex *)output_items[0];
80 unsigned int unoccupied_carriers = d_fft_length - d_occupied_carriers;
81 unsigned int zeros_on_left = (unsigned)ceil(unoccupied_carriers/2.0);
83 //printf("OFDM BPSK Mapper: ninput_items: %d noutput_items: %d\n", ninput_items[0], noutput_items);
90 d_msg = d_msgq->delete_head(); // block, waiting for a message
95 if((d_msg->length() == 0) && (d_msg->type() == 1)) {
101 if(output_items.size() == 2) {
102 char *sig = (char *)output_items[1];
103 if(d_header_sent == 1) {
111 // Build a single symbol:
113 // Initialize all bins to 0 to set unused carriers
114 memset(out, 0, d_fft_length*sizeof(gr_complex));
116 if(d_header_sent == 0) {
117 for(i=0; i < d_occupied_carriers; i++) {
118 out[i+zeros_on_left] = d_known_symbol1[i];
125 if(d_header_sent == 1) {
126 for(i=0; i < d_occupied_carriers; i++) {
127 out[i+zeros_on_left] = d_known_symbol2[i];
135 while((d_msg_offset < d_msg->length()) && (i < d_occupied_carriers)) {
136 unsigned char bit = (d_msg->msg()[d_msg_offset] >> (d_bit_offset)) & 0x01;
137 out[i + zeros_on_left] = gr_complex(-1+2*(bit));
140 if(d_bit_offset == 8) {
146 // Ran out of data to put in symbol
147 if (d_msg_offset == d_msg->length()) {
148 while(i < d_occupied_carriers) { // finish filling out the symbol
149 out[i + zeros_on_left] = gr_complex(randombit(),0);
153 if (d_msg->type() == 1) // type == 1 sets EOF
155 d_msg.reset(); // finished packet, free message
157 assert(d_bit_offset == 0);
158 return 1; // produced one symbol
161 return 1; // produced symbol