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144 lines
4.2 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 <math.h>
#include <sys/time.h>
#include <unistd.h>
#include <assert.h>
#include <signal.h>
#include "liblte/rrc/rrc.h"
#include "liblte/phy/phy.h"
#include "liblte/cuhd/cuhd.h"
#include "cell_scanner.h"
/**********************************************************************
* Program arguments processing
***********************************************************************/
typedef struct {
int nof_subframes;
int force_N_id_2;
char *uhd_args;
float uhd_freq;
}prog_args_t;
void args_default(prog_args_t *args) {
args->nof_subframes = -1;
args->force_N_id_2 = -1; // Pick the best
args->uhd_args = "";
args->uhd_freq = -1.0;
}
void usage(prog_args_t *args, char *prog) {
printf("Usage: %s [alnv] -f rx_frequency (in Hz)\n", prog);
printf("\t-a UHD args [Default %s]\n", args->uhd_args);
printf("\t-l Force N_id_2 [Default best]\n");
printf("\t-n nof_subframes [Default %d]\n", args->nof_subframes);
printf("\t-v [set verbose to debug, default none]\n");
}
void parse_args(prog_args_t *args, int argc, char **argv) {
int opt;
args_default(args);
while ((opt = getopt(argc, argv, "alnvf")) != -1) {
switch (opt) {
case 'a':
args->uhd_args = argv[optind];
break;
case 'f':
args->uhd_freq = atof(argv[optind]);
break;
case 'n':
args->nof_subframes = atoi(argv[optind]);
break;
case 'l':
args->force_N_id_2 = atoi(argv[optind]);
break;
case 'v':
verbose++;
break;
default:
usage(args, argv[0]);
exit(-1);
}
}
if (args->uhd_freq < 0) {
usage(args, argv[0]);
exit(-1);
}
}
/**********************************************************************/
int main(int argc, char **argv) {
prog_args_t prog_args;
cell_scanner_result_t result;
cell_scanner_config_t cfg;
cell_scanner_t cs;
parse_args(&prog_args, argc, argv);
// Peak-to-sidelobe ratio (PSR) threshold for cell detection early stopping.
cfg.cell_detect_early_stop_threshold = 20.0; // This is a normal value.
// maximum 5 ms frames that will be scanned maximum in the case the threshold is not exceed
// ie for bad cells
cfg.pss_max_frames = 50; // this is 250 ms
// maximum 5 ms frames that will be received to decode the PBCH
// ie for bad cells
cfg.pbch_max_frames = 500; // this is 2500 ms
// Number of 1 ms subframes that will be used to compute rsrp, rsrq, snr, etc average
cfg.measure_avg_nof_frames = 1000; // 1 sec
cfg.uhd_args = prog_args.uhd_args;
// Init USRP
if (cell_scanner_init(&cs, &cfg)) {
fprintf(stderr, "Error initiating cell scanner\n");
exit(-1);
}
// Scan for a frequency
if (prog_args.force_N_id_2 < 0) {
// We have 2 options, either we scan for the three possible N_id_2 root sequences...
cell_scanner_all_cells(&cs, prog_args.uhd_freq, &result);
} else {
// or we scan for a single one.
cell_scanner_cell(&cs, prog_args.uhd_freq, prog_args.force_N_id_2, &result);
}
printf("\nResult: CellID: %d, PHYID: %d, RSRP: %.1f dBm, RSRQ: %.1f dB, SNR: %.1f dB\n",
result.cell_id, result.phy_cell.id,
10*log10(result.rsrp*1000), 10*log10(result.rsrq), 10*log10(result.snr));
}