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246 lines
5.8 KiB
C

/**
*
* \section COPYRIGHT
*
* Copyright 2013-2014 The libLTE Developers. See the
* COPYRIGHT file at the top-level directory of this distribution.
*
* \section LICENSE
*
* This file is part of the libLTE library.
*
* libLTE is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version.
*
* libLTE 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 Lesser General Public License for more details.
*
* A copy of the GNU Lesser General Public License can be found in
* the LICENSE file in the top-level directory of this distribution
* and at http://www.gnu.org/licenses/.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>
#include "liblte/phy/phy.h"
char *input_file_name = NULL;
lte_cell_t cell = {
6, // nof_prb
2, // nof_ports
150, // cell_id
CPNORM, // cyclic prefix
R_1, // PHICH resources
PHICH_NORM // PHICH length
};
int nof_frames = 1;
uint8_t bch_payload_file[BCH_PAYLOAD_LEN] = {0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
#define FLEN (10*SF_LEN(lte_symbol_sz(cell.nof_prb)))
filesource_t fsrc;
cf_t *input_buffer, *fft_buffer, *ce[MAX_PORTS];
pbch_t pbch;
lte_fft_t fft;
chest_dl_t chest;
void usage(char *prog) {
printf("Usage: %s [vcoe] -i input_file\n", prog);
printf("\t-c cell_id [Default %d]\n", cell.id);
printf("\t-p nof_prb [Default %d]\n", cell.nof_prb);
printf("\t-e Set extended prefix [Default Normal]\n");
printf("\t-n nof_frames [Default %d]\n", nof_frames);
printf("\t-v [set verbose to debug, default none]\n");
}
void parse_args(int argc, char **argv) {
int opt;
while ((opt = getopt(argc, argv, "ivcpne")) != -1) {
switch(opt) {
case 'i':
input_file_name = argv[optind];
break;
case 'c':
cell.id = atoi(argv[optind]);
break;
case 'p':
cell.nof_prb = atoi(argv[optind]);
break;
case 'n':
nof_frames = atoi(argv[optind]);
break;
case 'v':
verbose++;
break;
case 'e':
cell.cp = CPEXT;
break;
default:
usage(argv[0]);
exit(-1);
}
}
if (!input_file_name) {
usage(argv[0]);
exit(-1);
}
}
int base_init() {
int i;
if (filesource_init(&fsrc, input_file_name, COMPLEX_FLOAT_BIN)) {
fprintf(stderr, "Error opening file %s\n", input_file_name);
exit(-1);
}
input_buffer = malloc(FLEN * sizeof(cf_t));
if (!input_buffer) {
perror("malloc");
exit(-1);
}
fft_buffer = malloc(SF_LEN_RE(cell.nof_prb, cell.cp) * sizeof(cf_t));
if (!fft_buffer) {
perror("malloc");
return -1;
}
for (i=0;i<cell.nof_ports;i++) {
ce[i] = malloc(SF_LEN_RE(cell.nof_prb, cell.cp) * sizeof(cf_t));
if (!ce[i]) {
perror("malloc");
return -1;
}
}
if (!lte_cell_isvalid(&cell)) {
fprintf(stderr, "Invalid cell properties\n");
return -1;
}
if (chest_dl_init(&chest, cell)) {
fprintf(stderr, "Error initializing equalizer\n");
return -1;
}
if (lte_fft_init(&fft, cell.cp, cell.nof_prb)) {
fprintf(stderr, "Error initializing FFT\n");
return -1;
}
if (pbch_init(&pbch, cell)) {
fprintf(stderr, "Error initiating PBCH\n");
return -1;
}
DEBUG("Memory init OK\n",0);
return 0;
}
void base_free() {
int i;
filesource_free(&fsrc);
free(input_buffer);
free(fft_buffer);
filesource_free(&fsrc);
for (i=0;i<cell.nof_ports;i++) {
free(ce[i]);
}
chest_dl_free(&chest);
lte_fft_free(&fft);
pbch_free(&pbch);
}
int main(int argc, char **argv) {
uint8_t bch_payload[BCH_PAYLOAD_LEN];
int n;
uint32_t nof_tx_ports, sfn_offset;
cf_t *ce_slot1[MAX_PORTS];
if (argc < 3) {
usage(argv[0]);
exit(-1);
}
parse_args(argc,argv);
if (base_init()) {
fprintf(stderr, "Error initializing receiver\n");
exit(-1);
}
int frame_cnt = 0;
int nof_decoded_mibs = 0;
int nread = 0;
do {
nread = filesource_read(&fsrc, input_buffer, FLEN);
if (nread > 0) {
// process 1st subframe only
lte_fft_run_sf(&fft, input_buffer, fft_buffer);
/* Get channel estimates for each port */
chest_dl_estimate(&chest, fft_buffer, ce, 0);
INFO("Decoding PBCH\n", 0);
for (int i=0;i<MAX_PORTS;i++) {
ce_slot1[i] = &ce[i][SLOT_LEN_RE(cell.nof_prb, cell.cp)];
}
pbch_decode_reset(&pbch);
n = pbch_decode(&pbch, &fft_buffer[SLOT_LEN_RE(cell.nof_prb, cell.cp)],
ce_slot1, chest_dl_get_noise_estimate(&chest),
bch_payload, &nof_tx_ports, &sfn_offset);
if (n == 1) {
nof_decoded_mibs++;
} else if (n < 0) {
fprintf(stderr, "Error decoding PBCH\n");
exit(-1);
}
frame_cnt++;
} else if (nread < 0) {
fprintf(stderr, "Error reading from file\n");
exit(-1);
}
} while(nread > 0 && frame_cnt < nof_frames);
base_free();
if (frame_cnt == 1) {
if (n == 0) {
printf("Could not decode PBCH\n");
exit(-1);
} else {
printf("MIB decoded OK. Nof ports: %d. SFN offset: %d Payload: ", nof_tx_ports, sfn_offset);
vec_fprint_hex(stdout, bch_payload, BCH_PAYLOAD_LEN);
if (nof_tx_ports == 2 && sfn_offset == 0 && !memcmp(bch_payload, bch_payload_file, BCH_PAYLOAD_LEN)) {
printf("This is the signal.1.92M.dat file\n");
exit(0);
} else {
printf("This is an unknown file\n");
exit(-1);
}
}
} else {
printf("Decoded %d/%d MIBs\n", nof_decoded_mibs, frame_cnt);
}
}