/* Returns 1 if the SSS is found, 0 if not and -1 if there is not enough space
* to correlate
*/
int sync_sss(srslte_sync_t *q, cf_t *input, uint32_t peak_pos, srslte_cp_t cp) {
int sss_idx, ret;
srslte_sss_synch_set_N_id_2(&q->sss, q->N_id_2);
/* Make sure we have enough room to find SSS sequence */
sss_idx = (int) peak_pos-2*q->fft_size-SRSLTE_CP_LEN(q->fft_size, (SRSLTE_CP_ISNORM(q->cp)?SRSLTE_CP_NORM_LEN:SRSLTE_CP_EXT_LEN));
if (sss_idx < 0) {
DEBUG("Not enough room to decode CP SSS (sss_idx=%d, peak_pos=%d)\n", sss_idx, peak_pos);
return SRSLTE_ERROR;
}
DEBUG("Searching SSS around sss_idx: %d, peak_pos: %d\n", sss_idx, peak_pos);
switch(q->sss_alg) {
case SSS_DIFF:
srslte_sss_synch_m0m1_diff(&q->sss, &input[sss_idx], &q->m0, &q->m0_value, &q->m1, &q->m1_value);
break;
case SSS_PARTIAL_3:
srslte_sss_synch_m0m1_partial(&q->sss, &input[sss_idx], 3, NULL, &q->m0, &q->m0_value, &q->m1, &q->m1_value);
break;
case SSS_FULL:
srslte_sss_synch_m0m1_partial(&q->sss, &input[sss_idx], 1, NULL, &q->m0, &q->m0_value, &q->m1, &q->m1_value);
break;
}
q->sf_idx = srslte_sss_synch_subframe(q->m0, q->m1);
ret = srslte_sss_synch_N_id_1(&q->sss, q->m0, q->m1);
if (ret >= 0) {
q->N_id_1 = (uint32_t) ret;
DEBUG("SSS detected N_id_1=%d, sf_idx=%d, %s CP\n",
q->N_id_1, q->sf_idx, SRSLTE_CP_ISNORM(q->cp)?"Normal":"Extended");
return 1;
} else {
q->N_id_1 = 1000;
return SRSLTE_SUCCESS;
}
}
int main(int argc, char **argv) {
cf_t *buffer;
int frame_cnt, n;
void *uhd;
srslte_pss_synch_t pss;
srslte_cfo_t cfocorr, cfocorr64;
srslte_sss_synch_t sss;
int32_t flen;
int peak_idx, last_peak;
float peak_value;
float mean_peak;
uint32_t nof_det, nof_nodet, nof_nopeak, nof_nopeakdet;
cf_t ce[SRSLTE_PSS_LEN];
parse_args(argc, argv);
if (N_id_2_sync == -1) {
N_id_2_sync = cell_id%3;
}
uint32_t N_id_2 = cell_id%3;
uint32_t N_id_1 = cell_id/3;
#ifndef DISABLE_GRAPHICS
if (!disable_plots)
init_plots();
#endif
float srate = 15000.0*fft_size;
flen = srate*5/1000;
printf("Opening UHD device...\n");
if (cuhd_open(uhd_args, &uhd)) {
fprintf(stderr, "Error opening uhd\n");
exit(-1);
}
if (srate < 10e6) {
cuhd_set_master_clock_rate(uhd, 4*srate);
} else {
cuhd_set_master_clock_rate(uhd, srate);
}
printf("Set RX rate: %.2f MHz\n", cuhd_set_rx_srate(uhd, srate) / 1000000);
printf("Set RX gain: %.1f dB\n", cuhd_set_rx_gain(uhd, uhd_gain));
printf("Set RX freq: %.2f MHz\n", cuhd_set_rx_freq(uhd, uhd_freq) / 1000000);
cuhd_rx_wait_lo_locked(uhd);
buffer = malloc(sizeof(cf_t) * flen * 2);
if (!buffer) {
perror("malloc");
exit(-1);
}
if (srslte_pss_synch_init_fft(&pss, flen, fft_size)) {
fprintf(stderr, "Error initiating PSS\n");
exit(-1);
}
if (srslte_pss_synch_set_N_id_2(&pss, N_id_2_sync)) {
fprintf(stderr, "Error setting N_id_2=%d\n",N_id_2_sync);
exit(-1);
}
srslte_cfo_init(&cfocorr, flen);
srslte_cfo_init(&cfocorr64, flen);
if (srslte_sss_synch_init(&sss, fft_size)) {
fprintf(stderr, "Error initializing SSS object\n");
return SRSLTE_ERROR;
}
srslte_sss_synch_set_N_id_2(&sss, N_id_2);
printf("N_id_2: %d\n", N_id_2);
cuhd_start_rx_stream(uhd);
printf("Frame length %d samples\n", flen);
printf("PSS detection threshold: %.2f\n", threshold);
nof_det = nof_nodet = nof_nopeak = nof_nopeakdet = 0;
frame_cnt = 0;
last_peak = 0;
mean_peak = 0;
int peak_offset = 0;
float cfo;
float mean_cfo = 0;
uint32_t m0, m1;
uint32_t sss_error1 = 0, sss_error2 = 0, sss_error3 = 0;
uint32_t cp_is_norm = 0;
srslte_sync_t ssync;
bzero(&ssync, sizeof(srslte_sync_t));
ssync.fft_size = fft_size;
while(frame_cnt < nof_frames || nof_frames == -1) {
n = cuhd_recv(uhd, buffer, flen - peak_offset, 1);
if (n < 0) {
fprintf(stderr, "Error receiving samples\n");
exit(-1);
}
peak_idx = srslte_pss_synch_find_pss(&pss, buffer, &peak_value);
if (peak_idx < 0) {
fprintf(stderr, "Error finding PSS peak\n");
exit(-1);
}
mean_peak = SRSLTE_VEC_CMA(peak_value, mean_peak, frame_cnt);
if (peak_value >= threshold) {
nof_det++;
if (peak_idx >= fft_size) {
// Estimate CFO
cfo = srslte_pss_synch_cfo_compute(&pss, &buffer[peak_idx-fft_size]);
mean_cfo = SRSLTE_VEC_CMA(cfo, mean_cfo, frame_cnt);
// Correct CFO
srslte_cfo_correct(&cfocorr, buffer, buffer, -mean_cfo / fft_size);
// Estimate channel
if (srslte_pss_synch_chest(&pss, &buffer[peak_idx-fft_size], ce)) {
fprintf(stderr, "Error computing channel estimation\n");
exit(-1);
}
// Find SSS
int sss_idx = peak_idx-2*fft_size-(SRSLTE_CP_ISNORM(cp)?SRSLTE_CP_LEN(fft_size, SRSLTE_CP_NORM_LEN):SRSLTE_CP_LEN(fft_size, SRSLTE_CP_EXT_LEN));
if (sss_idx >= 0 && sss_idx < flen-fft_size) {
srslte_sss_synch_m0m1_partial(&sss, &buffer[sss_idx], 3, NULL, &m0, &m0_value, &m1, &m1_value);
if (srslte_sss_synch_N_id_1(&sss, m0, m1) != N_id_1) {
sss_error2++;
}
INFO("Partial N_id_1: %d\n", srslte_sss_synch_N_id_1(&sss, m0, m1));
srslte_sss_synch_m0m1_diff(&sss, &buffer[sss_idx], &m0, &m0_value, &m1, &m1_value);
if (srslte_sss_synch_N_id_1(&sss, m0, m1) != N_id_1) {
sss_error3++;
}
INFO("Diff N_id_1: %d\n", srslte_sss_synch_N_id_1(&sss, m0, m1));
srslte_sss_synch_m0m1_partial(&sss, &buffer[sss_idx], 1, NULL, &m0, &m0_value, &m1, &m1_value);
if (srslte_sss_synch_N_id_1(&sss, m0, m1) != N_id_1) {
sss_error1++;
}
INFO("Full N_id_1: %d\n", srslte_sss_synch_N_id_1(&sss, m0, m1));
}
// Estimate CP
if (peak_idx > 2*(fft_size + SRSLTE_CP_LEN_EXT(fft_size))) {
srslte_cp_t cp = srslte_sync_detect_cp(&ssync, buffer, peak_idx);
if (SRSLTE_CP_ISNORM(cp)) {
cp_is_norm++;
}
}
} else {
INFO("No space for CFO computation. Frame starts at \n",peak_idx);
}
if(srslte_sss_synch_subframe(m0,m1) == 0)
{
#ifndef DISABLE_GRAPHICS
if (!disable_plots)
do_plots_sss(sss.corr_output_m0, sss.corr_output_m1);
#endif
}
} else {
nof_nodet++;
}
if (frame_cnt > 100) {
if (abs(last_peak-peak_idx) > 4) {
if (peak_value >= threshold) {
nof_nopeakdet++;
}
nof_nopeak++;
}
}
frame_cnt++;
printf("[%5d]: Pos: %5d, PSR: %4.1f (~%4.1f) Pdet: %4.2f, "
"FA: %4.2f, CFO: %+4.1f KHz SSSmiss: %4.2f/%4.2f/%4.2f CPNorm: %.0f%%\r",
frame_cnt,
peak_idx,
peak_value, mean_peak,
(float) nof_det/frame_cnt,
(float) nof_nopeakdet/frame_cnt, mean_cfo*15,
(float) sss_error1/nof_det,(float) sss_error2/nof_det,(float) sss_error3/nof_det,
(float) cp_is_norm/nof_det * 100);
if (SRSLTE_VERBOSE_ISINFO()) {
printf("\n");
}
#ifndef DISABLE_GRAPHICS
if (!disable_plots)
do_plots(pss.conv_output_avg, pss.conv_output_avg[peak_idx], pss.fft_size+pss.frame_size-1, ce);
#endif
last_peak = peak_idx;
}
srslte_pss_synch_free(&pss);
free(buffer);
cuhd_close(uhd);
printf("Ok\n");
exit(0);
}