mirror of https://github.com/PentHertz/srsLTE.git
560 lines
14 KiB
C
560 lines
14 KiB
C
/**
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*
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* \section COPYRIGHT
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*
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* Copyright 2013-2014 The libLTE Developers. See the
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* COPYRIGHT file at the top-level directory of this distribution.
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*
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* \section LICENSE
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*
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* This file is part of the libLTE library.
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*
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* libLTE is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as
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* published by the Free Software Foundation, either version 3 of
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* the License, or (at your option) any later version.
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*
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* libLTE is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* A copy of the GNU Lesser General Public License can be found in
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* the LICENSE file in the top-level directory of this distribution
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* and at http://www.gnu.org/licenses/.
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <strings.h>
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#include <unistd.h>
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#include <math.h>
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#include <sys/time.h>
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#include <unistd.h>
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#include "lte.h"
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//#define DISABLE_UHD
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#ifndef DISABLE_UHD
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#include "cuhd.h"
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#endif
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#define MHZ 1000000
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#define SAMP_FREQ 1920000
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#define RSSI_FS 1000000
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#define FLEN 9600
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#define FLEN_PERIOD 0.005
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#define RSSI_DECIM 20
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#define IS_SIGNAL(i) (10*log10f(rssi[i]) + 30 > rssi_threshold)
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int band, earfcn=-1;
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float find_threshold = 10.0, track_threshold = 8.0;
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int earfcn_start=-1, earfcn_end = -1;
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float rssi_threshold = -45.0;
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int max_track_lost=9;
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int nof_frames_find=20, nof_frames_track=100, nof_samples_rssi=50000;
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int track_len=500;
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cf_t *input_buffer, *fft_buffer, *ce[MAX_PORTS];
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pbch_t pbch;
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lte_fft_t fft;
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chest_t chest;
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sync_t sfind, strack;
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cfo_t cfocorr;
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float *cfo_v;
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int *idx_v, *idx_valid, *t;
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float *p2a_v;
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void *uhd;
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int nof_bands;
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float uhd_gain = 20.0;
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#define MAX_EARFCN 1000
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lte_earfcn_t channels[MAX_EARFCN];
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float rssi[MAX_EARFCN];
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float rssi_d[MAX_EARFCN/RSSI_DECIM];
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float freqs[MAX_EARFCN];
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float cfo[MAX_EARFCN];
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float p2a[MAX_EARFCN];
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enum sync_state {INIT, FIND, TRACK, MIB, DONE};
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void usage(char *prog) {
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printf("Usage: %s [seRrFfTtgv] -b band\n", prog);
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printf("\t-s earfcn_start [Default All]\n");
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printf("\t-e earfcn_end [Default All]\n");
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printf("\t-R rssi_nof_samples [Default %d]\n", nof_samples_rssi);
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printf("\t-r rssi_threshold [Default %.2f dBm]\n", rssi_threshold);
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printf("\t-F pss_find_nof_frames [Default %d]\n", nof_frames_find);
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printf("\t-f pss_find_threshold [Default %.2f]\n", find_threshold);
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printf("\t-T pss_track_nof_frames [Default %d]\n", nof_frames_track);
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printf("\t-t pss_track_threshold [Default %.2f]\n", track_threshold);
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printf("\t-l pss_track_len [Default %d]\n", track_len);
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printf("\t-g gain [Default %.2f dB]\n", uhd_gain);
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printf("\t-v [set verbose to debug, default none]\n");
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}
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void parse_args(int argc, char **argv) {
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int opt;
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while ((opt = getopt(argc, argv, "bseRrFfTtgv")) != -1) {
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switch(opt) {
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case 'b':
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band = atoi(argv[optind]);
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break;
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case 's':
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earfcn_start = atoi(argv[optind]);
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break;
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case 'e':
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earfcn_end = atoi(argv[optind]);
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break;
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case 'R':
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nof_samples_rssi = atoi(argv[optind]);
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break;
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case 'r':
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rssi_threshold = -atof(argv[optind]);
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break;
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case 'F':
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nof_frames_find = atoi(argv[optind]);
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break;
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case 'f':
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find_threshold = atof(argv[optind]);
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break;
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case 'T':
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nof_frames_track = atoi(argv[optind]);
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break;
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case 't':
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track_threshold = atof(argv[optind]);
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break;
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case 'g':
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uhd_gain = atof(argv[optind]);
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break;
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case 'v':
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verbose++;
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break;
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default:
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usage(argv[0]);
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exit(-1);
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}
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}
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}
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int base_init(int frame_length) {
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int i;
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input_buffer = malloc(2 * frame_length * sizeof(cf_t));
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if (!input_buffer) {
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perror("malloc");
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return -1;
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}
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fft_buffer = malloc(CPNORM_NSYMB * 72 * sizeof(cf_t));
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if (!fft_buffer) {
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perror("malloc");
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return -1;
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}
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for (i=0;i<MAX_PORTS;i++) {
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ce[i] = malloc(CPNORM_NSYMB * 72 * sizeof(cf_t));
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if (!ce[i]) {
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perror("malloc");
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return -1;
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}
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}
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if (sync_init(&sfind, FLEN)) {
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fprintf(stderr, "Error initiating PSS/SSS\n");
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return -1;
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}
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if (sync_init(&strack, track_len)) {
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fprintf(stderr, "Error initiating PSS/SSS\n");
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return -1;
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}
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if (chest_init(&chest, LINEAR, CPNORM, 6, MAX_PORTS)) {
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fprintf(stderr, "Error initializing equalizer\n");
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return -1;
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}
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if (lte_fft_init(&fft, CPNORM, 6)) {
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fprintf(stderr, "Error initializing FFT\n");
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return -1;
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}
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if (cfo_init(&cfocorr, FLEN)) {
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fprintf(stderr, "Error initiating CFO\n");
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return -1;
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}
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idx_v = malloc(nof_frames_track * sizeof(int));
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if (!idx_v) {
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perror("malloc");
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return -1;
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}
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idx_valid = malloc(nof_frames_track * sizeof(int));
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if (!idx_valid) {
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perror("malloc");
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return -1;
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}
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t = malloc(nof_frames_track * sizeof(int));
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if (!t) {
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perror("malloc");
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return -1;
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}
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cfo_v = malloc(nof_frames_track * sizeof(float));
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if (!cfo_v) {
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perror("malloc");
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return -1;
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}
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p2a_v = malloc(nof_frames_track * sizeof(float));
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if (!p2a_v) {
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perror("malloc");
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return -1;
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}
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bzero(cfo, sizeof(float) * MAX_EARFCN);
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bzero(p2a, sizeof(float) * MAX_EARFCN);
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/* open UHD device */
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#ifndef DISABLE_UHD
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printf("Opening UHD device...\n");
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if (cuhd_open("",&uhd)) {
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fprintf(stderr, "Error opening uhd\n");
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return -1;
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}
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#endif
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return 0;
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}
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void base_free() {
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int i;
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#ifndef DISABLE_UHD
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cuhd_close(uhd);
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#endif
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sync_free(&sfind);
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sync_free(&strack);
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lte_fft_free(&fft);
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chest_free(&chest);
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cfo_free(&cfocorr);
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free(input_buffer);
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free(fft_buffer);
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for (i=0;i<MAX_PORTS;i++) {
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free(ce[i]);
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}
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free(idx_v);
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free(idx_valid);
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free(t);
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free(cfo_v);
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free(p2a_v);
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}
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float mean_valid(int *idx_v, float *x, int nof_frames) {
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int i;
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float mean = 0;
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int n = 0;
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for (i=0;i<nof_frames;i++) {
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if (idx_v[i] != -1) {
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mean += x[i];
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n++;
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}
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}
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if (n > 0) {
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return mean/n;
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} else {
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return 0.0;
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}
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}
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int preprocess_idx(int *in, int *out, int *period, int len) {
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int i, n;
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n=0;
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for (i=0;i<len;i++) {
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if (in[i] != -1) {
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out[n] = in[i];
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period[n] = i;
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n++;
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}
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}
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return n;
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}
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int rssi_scan() {
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int n=0;
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int i;
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if (nof_bands > 100) {
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/* scan every Mhz, that is 10 freqs */
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for (i=0;i<nof_bands;i+=RSSI_DECIM) {
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freqs[n] = channels[i].fd * MHZ;
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n++;
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}
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#ifndef DISABLE_UHD
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if (cuhd_rssi_scan(uhd, freqs, rssi_d, n, (double) RSSI_FS, nof_samples_rssi)) {
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fprintf(stderr, "Error while doing RSSI scan\n");
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return -1;
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}
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#endif
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/* linearly interpolate the rssi vector */
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interp_linear_f(rssi_d, rssi, RSSI_DECIM, n);
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} else {
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for (i=0;i<nof_bands;i++) {
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freqs[i] = channels[i].fd * MHZ;
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}
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#ifndef DISABLE_UHD
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if (cuhd_rssi_scan(uhd, freqs, rssi, nof_bands, (double) RSSI_FS, nof_samples_rssi)) {
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fprintf(stderr, "Error while doing RSSI scan\n");
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return -1;
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}
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#endif
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n = nof_bands;
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}
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return n;
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}
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int mib_decoder_init(int cell_id) {
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if (chest_ref_LTEDL(&chest, cell_id)) {
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fprintf(stderr, "Error initializing reference signal\n");
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return -1;
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}
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if (pbch_init(&pbch, 6, cell_id, CPNORM)) {
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fprintf(stderr, "Error initiating PBCH\n");
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return -1;
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}
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DEBUG("PBCH initiated cell_id=%d\n", cell_id);
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return 0;
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}
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int mib_decoder_run(cf_t *input, pbch_mib_t *mib) {
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int i;
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lte_fft_run(&fft, input, fft_buffer);
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/* Get channel estimates for each port */
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for (i=0;i<MAX_PORTS;i++) {
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chest_ce_slot_port(&chest, fft_buffer, ce[i], 1, i);
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}
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DEBUG("Decoding PBCH\n", 0);
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return pbch_decode(&pbch, fft_buffer, ce, 1, mib);
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}
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int main(int argc, char **argv) {
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int frame_cnt, valid_frames;
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int freq;
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int cell_id;
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float max_peak_to_avg;
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float sfo;
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int find_idx, track_idx, last_found;
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enum sync_state state;
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int n;
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int mib_attempts;
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int nslot;
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pbch_mib_t mib;
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if (argc < 3) {
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usage(argv[0]);
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exit(-1);
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}
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parse_args(argc,argv);
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if (base_init(FLEN)) {
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fprintf(stderr, "Error initializing memory\n");
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exit(-1);
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}
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sync_pss_det_peak_to_avg(&sfind);
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sync_pss_det_peak_to_avg(&strack);
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nof_bands = lte_band_get_fd_band(band, channels, earfcn_start, earfcn_end, MAX_EARFCN);
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printf("RSSI scan: %d freqs in band %d, RSSI threshold %.2f dBm\n", nof_bands, band, rssi_threshold);
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n = rssi_scan();
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if (n == -1) {
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exit(-1);
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}
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printf("\nDone. Starting PSS search on %d channels\n", n);
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usleep(500000);
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INFO("Setting sampling frequency %.2f MHz\n", (float) SAMP_FREQ/MHZ);
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#ifndef DISABLE_UHD
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cuhd_set_rx_srate(uhd, SAMP_FREQ);
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cuhd_set_rx_gain(uhd, uhd_gain);
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#endif
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freq=0;
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state = INIT;
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nslot = 0;
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sfo = 0;
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find_idx = 0;
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frame_cnt = 0;
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max_peak_to_avg = -1;
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last_found = 0;
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cell_id = 0;
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while(freq<nof_bands) {
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/* scan only bands above rssi_threshold */
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if (!IS_SIGNAL(freq)) {
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INFO("[%3d/%d]: Skipping EARFCN %d %.2f MHz RSSI %.2f dB\n", freq, nof_bands,
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channels[freq].id, channels[freq].fd,10*log10f(rssi[freq]) + 30);
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freq++;
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} else {
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if (state != INIT && state != DONE) {
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#ifndef DISABLE_UHD
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DEBUG(" ----- RECEIVING %d SAMPLES ---- \n", FLEN);
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cuhd_recv(uhd, &input_buffer[FLEN], FLEN, 1);
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#endif
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}
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switch(state) {
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case INIT:
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DEBUG("Stopping receiver...\n",0);
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#ifndef DISABLE_UHD
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cuhd_stop_rx_stream(uhd);
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/* set freq */
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cuhd_set_rx_freq(uhd, (double) channels[freq].fd * MHZ);
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cuhd_rx_wait_lo_locked(uhd);
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DEBUG("Set freq to %.3f MHz\n", (double) channels[freq].fd);
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DEBUG("Starting receiver...\n",0);
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cuhd_start_rx_stream(uhd);
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#endif
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/* init variables */
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frame_cnt = 0;
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max_peak_to_avg = -1;
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cell_id = -1;
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/* receive first frame */
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#ifndef DISABLE_UHD
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cuhd_recv(uhd, input_buffer, FLEN, 1);
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#endif
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/* set find_threshold and go to FIND state */
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sync_set_threshold(&sfind, find_threshold);
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sync_force_N_id_2(&sfind, -1);
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state = FIND;
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break;
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case FIND:
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/* find peak in all frame */
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find_idx = sync_run(&sfind, &input_buffer[FLEN]);
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DEBUG("[%3d/%d]: PAR=%.2f\n", freq, nof_bands, sync_get_peak_to_avg(&sfind));
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if (find_idx != -1) {
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/* if found peak, go to track and set lower threshold */
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frame_cnt = -1;
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last_found = 0;
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max_peak_to_avg = -1;
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sync_set_threshold(&strack, track_threshold);
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sync_force_N_id_2(&strack, sync_get_N_id_2(&sfind));
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cell_id = sync_get_cell_id(&sfind);
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state = TRACK;
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INFO("[%3d/%d]: EARFCN %d Freq. %.2f MHz PSS found PAR %.2f dB\n", freq, nof_bands,
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channels[freq].id, channels[freq].fd,
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10*log10f(sync_get_peak_to_avg(&sfind)));
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} else {
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if (frame_cnt >= nof_frames_find) {
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state = INIT;
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freq++;
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}
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}
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break;
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case TRACK:
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INFO("Tracking PSS find_idx %d offset %d\n", find_idx, find_idx - track_len);
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track_idx = sync_run(&strack, &input_buffer[FLEN + find_idx - track_len]);
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p2a_v[frame_cnt] = sync_get_peak_to_avg(&strack);
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/* save cell id for the best peak-to-avg */
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if (p2a_v[frame_cnt] > max_peak_to_avg) {
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max_peak_to_avg = p2a_v[frame_cnt];
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cell_id = sync_get_cell_id(&strack);
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}
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if (track_idx != -1) {
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cfo_v[frame_cnt] = sync_get_cfo(&strack);
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last_found = frame_cnt;
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find_idx += track_idx - track_len;
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idx_v[frame_cnt] = find_idx;
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nslot = sync_get_slot_id(&strack);
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} else {
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idx_v[frame_cnt] = -1;
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cfo_v[frame_cnt] = 0.0;
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}
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/* if we missed to many PSS it is not a cell, next freq */
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if (frame_cnt - last_found > max_track_lost) {
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INFO("\n[%3d/%d]: EARFCN %d Freq. %.2f MHz %d frames lost\n", freq, nof_bands,
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channels[freq].id, channels[freq].fd, frame_cnt - last_found);
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state = INIT;
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freq++;
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} else if (frame_cnt >= nof_frames_track) {
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mib_decoder_init(cell_id);
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cfo[freq] = mean_valid(idx_v, cfo_v, frame_cnt);
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p2a[freq] = mean_valid(idx_v, p2a_v, frame_cnt);
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valid_frames = preprocess_idx(idx_v, idx_valid, t, frame_cnt);
|
|
sfo = sfo_estimate_period(idx_valid, t, valid_frames, FLEN_PERIOD);
|
|
|
|
state = MIB;
|
|
nslot=(nslot+10)%20;
|
|
}
|
|
break;
|
|
case MIB:
|
|
INFO("Finding MIB at freq %.2f Mhz offset=%d, cell_id=%d, slot_idx=%d\n", channels[freq].fd, find_idx, cell_id, nslot);
|
|
|
|
// TODO: Correct SFO
|
|
|
|
// Correct CFO
|
|
INFO("Correcting CFO=%.4f\n", cfo[freq]);
|
|
cfo_correct(&cfocorr, &input_buffer[FLEN], (-cfo[freq])/128);
|
|
|
|
if (nslot == 0) {
|
|
if (mib_decoder_run(&input_buffer[FLEN+find_idx], &mib)) {
|
|
INFO("MIB detected attempt=%d\n", mib_attempts);
|
|
state = DONE;
|
|
} else {
|
|
INFO("MIB not detected attempt=%d\n", mib_attempts);
|
|
if (mib_attempts == 0) {
|
|
freq++;
|
|
state = INIT;
|
|
}
|
|
}
|
|
mib_attempts++;
|
|
}
|
|
nslot = (nslot+10)%20;
|
|
|
|
|
|
break;
|
|
case DONE:
|
|
printf("\n[%3d/%d]: FOUND EARFCN %d Freq. %.2f MHz. "
|
|
"PAR %2.2f dB, CFO=%+.2f KHz, SFO=%+2.3f KHz, CELL_ID=%3d\n", freq, nof_bands,
|
|
channels[freq].id, channels[freq].fd,
|
|
10*log10f(p2a[freq]), cfo[freq] * 15, sfo / 1000, cell_id);
|
|
pbch_mib_fprint(stdout, &mib);
|
|
state = INIT;
|
|
freq++;
|
|
break;
|
|
}
|
|
|
|
/** FIXME: This is not necessary at all */
|
|
if (state == TRACK || state == FIND) {
|
|
memcpy(input_buffer, &input_buffer[FLEN], FLEN * sizeof(cf_t));
|
|
}
|
|
frame_cnt++;
|
|
}
|
|
}
|
|
|
|
base_free();
|
|
|
|
printf("\n\nDone\n");
|
|
exit(0);
|
|
}
|
|
|