uint32_t get_pucch_symbol(uint32_t m, srslte_pucch_format_t format, srslte_cp_t cp) {
switch (format) {
case SRSLTE_PUCCH_FORMAT_1:
case SRSLTE_PUCCH_FORMAT_1A:
case SRSLTE_PUCCH_FORMAT_1B:
if (m < 5) {
if (SRSLTE_CP_ISNORM(cp)) {
return pucch_symbol_format1_cpnorm[m];
} else {
return pucch_symbol_format1_cpext[m];
}
}
break;
case SRSLTE_PUCCH_FORMAT_2:
case SRSLTE_PUCCH_FORMAT_2A:
case SRSLTE_PUCCH_FORMAT_2B:
if (m < 6) {
if (SRSLTE_CP_ISNORM(cp)) {
return pucch_symbol_format2_cpnorm[m];
} else {
return pucch_symbol_format2_cpext[m];
}
}
break;
}
return 0;
}
uint32_t srslte_phich_nsf(srslte_phich_t *q) {
if (SRSLTE_CP_ISNORM(q->cell.cp)) {
return SRSLTE_PHICH_NORM_NSF;
} else {
return SRSLTE_PHICH_EXT_NSF;
}
}
/**
* Returns the number of REGs in a PRB
* 36.211 Section 6.2.4
*/
int regs_num_x_symbol(uint32_t symbol, uint32_t nof_port, srslte_cp_t cp) {
switch (symbol) {
case 0:
return 2;
case 1:
switch (nof_port) {
case 1:
case 2:
return 3;
case 4:
return 2;
default:
fprintf(stderr, "Invalid number of ports %d\n", nof_port);
return SRSLTE_ERROR;
}
break;
case 2:
return 3;
case 3:
if (SRSLTE_CP_ISNORM(cp)) {
return 3;
} else {
return 2;
}
default:
fprintf(stderr, "Invalid symbol %d\n", symbol);
return SRSLTE_ERROR;
}
}
/* Returns 1 if the SSS is found, 0 if not and -1 if there is not enough space
* to correlate
*/
int sync_sss_symbol(srslte_sync_t *q, const cf_t *input)
{
int ret;
srslte_sss_set_N_id_2(&q->sss, q->N_id_2);
switch(q->sss_alg) {
case SSS_DIFF:
srslte_sss_m0m1_diff(&q->sss, input, &q->m0, &q->m0_value, &q->m1, &q->m1_value);
break;
case SSS_PARTIAL_3:
srslte_sss_m0m1_partial(&q->sss, input, 3, NULL, &q->m0, &q->m0_value, &q->m1, &q->m1_value);
break;
case SSS_FULL:
srslte_sss_m0m1_partial(&q->sss, input, 1, NULL, &q->m0, &q->m0_value, &q->m1, &q->m1_value);
break;
}
q->sf_idx = srslte_sss_subframe(q->m0, q->m1);
ret = srslte_sss_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;
}
}
/* Map PUCCH symbols to physical resources according to 5.4.3 in 36.211 */
static int pucch_put(srslte_pucch_t *q, srslte_pucch_format_t format, uint32_t n_pucch, cf_t *output) {
int ret = SRSLTE_ERROR_INVALID_INPUTS;
if (q && output) {
ret = SRSLTE_ERROR;
uint32_t nsymbols = SRSLTE_CP_ISNORM(q->cell.cp)?SRSLTE_CP_NORM_NSYMB:SRSLTE_CP_EXT_NSYMB;
// Determine m
uint32_t m = srslte_pucch_m(&q->pucch_cfg, format, n_pucch, q->cell.cp);
uint32_t N_sf_0 = get_N_sf(format, 0, q->shortened);
for (uint32_t ns=0;ns<2;ns++) {
uint32_t N_sf = get_N_sf(format, ns%2, q->shortened);
// Determine n_prb
uint32_t n_prb = m/2;
if ((m+ns)%2) {
n_prb = q->cell.nof_prb-1-m/2;
}
if (n_prb < q->cell.nof_prb) {
for (uint32_t i=0;i<N_sf;i++) {
uint32_t l = get_pucch_symbol(i, format, q->cell.cp);
memcpy(&output[SRSLTE_RE_IDX(q->cell.nof_prb, l+ns*nsymbols, n_prb*SRSLTE_NRE)],
&q->z[i*SRSLTE_NRE+ns*N_sf_0*SRSLTE_NRE],
SRSLTE_NRE*sizeof(cf_t));
}
} else {
return SRSLTE_ERROR;
}
}
ret = SRSLTE_SUCCESS;
}
return ret;
}
/* Calculates alpha for format 1/a/b according to 5.5.2.2.2 (is_dmrs=true) or 5.4.1 (is_dmrs=false) of 36.211 */
float srslte_pucch_alpha_format1(uint32_t n_cs_cell[SRSLTE_NSLOTS_X_FRAME][SRSLTE_CP_NORM_NSYMB],
srslte_pucch_cfg_t *cfg,
uint32_t n_pucch,
srslte_cp_t cp, bool is_dmrs,
uint32_t ns, uint32_t l,
uint32_t *n_oc_ptr, uint32_t *n_prime_ns)
{
uint32_t c = SRSLTE_CP_ISNORM(cp)?3:2;
uint32_t N_prime = (n_pucch < c*cfg->N_cs/cfg->delta_pucch_shift)?cfg->N_cs:SRSLTE_NRE;
uint32_t n_prime = n_pucch;
if (n_pucch >= c*cfg->N_cs/cfg->delta_pucch_shift) {
n_prime = (n_pucch-c*cfg->N_cs/cfg->delta_pucch_shift)%(c*SRSLTE_NRE/cfg->delta_pucch_shift);
}
if (ns%2) {
if (n_pucch >= c*cfg->N_cs/cfg->delta_pucch_shift) {
n_prime = (c*(n_prime+1))%(c*SRSLTE_NRE/cfg->delta_pucch_shift+1)-1;
} else {
uint32_t d=SRSLTE_CP_ISNORM(cp)?2:0;
uint32_t h=(n_prime+d)%(c*N_prime/cfg->delta_pucch_shift);
n_prime = (h/c)+(h%c)*N_prime/cfg->delta_pucch_shift;
}
}
if (n_prime_ns) {
*n_prime_ns = n_prime;
}
uint32_t n_oc_div = (!is_dmrs && SRSLTE_CP_ISEXT(cp))?2:1;
uint32_t n_oc = n_prime*cfg->delta_pucch_shift/N_prime;
if (!is_dmrs && SRSLTE_CP_ISEXT(cp)) {
n_oc *= 2;
}
if (n_oc_ptr) {
*n_oc_ptr = n_oc;
}
uint32_t n_cs = 0;
if (SRSLTE_CP_ISNORM(cp)) {
n_cs = (n_cs_cell[ns][l]+(n_prime*cfg->delta_pucch_shift+(n_oc%cfg->delta_pucch_shift))%N_prime)%SRSLTE_NRE;
} else {
n_cs = (n_cs_cell[ns][l]+(n_prime*cfg->delta_pucch_shift+n_oc/n_oc_div)%N_prime)%SRSLTE_NRE;
}
return 2 * M_PI * (n_cs) / SRSLTE_NRE;
}
/**
* Transforms input samples into output OFDM symbols.
* Performs FFT on a each symbol and removes CP.
*/
void srslte_ofdm_rx_slot(srslte_ofdm_t *q, cf_t *input, cf_t *output) {
uint32_t i;
for (i=0;i<q->nof_symbols;i++) {
input += SRSLTE_CP_ISNORM(q->cp)?SRSLTE_CP_LEN_NORM(i, q->symbol_sz):SRSLTE_CP_LEN_EXT(q->symbol_sz);
srslte_dft_run_c(&q->fft_plan, input, q->tmp);
memcpy(output, &q->tmp[q->nof_guards], q->nof_re * sizeof(cf_t));
input += q->symbol_sz;
output += q->nof_re;
}
}
void srslte_sync_set_cp(srslte_sync_t *q, srslte_cp_t cp)
{
q->cp = cp;
q->cp_len = SRSLTE_CP_ISNORM(q->cp)?SRSLTE_CP_LEN_NORM(1,q->fft_size):SRSLTE_CP_LEN_EXT(q->fft_size);
if (q->frame_size < q->fft_size) {
q->nof_symbols = 1;
} else {
q->nof_symbols = q->frame_size/(q->fft_size+q->cp_len)-1;
}
}
/**
* Transforms input OFDM symbols into output samples.
* Performs FFT on a each symbol and adds CP.
*/
void srslte_ofdm_tx_slot(srslte_ofdm_t *q, cf_t *input, cf_t *output) {
uint32_t i, cp_len;
for (i=0;i<q->nof_symbols;i++) {
cp_len = SRSLTE_CP_ISNORM(q->cp)?SRSLTE_CP_LEN_NORM(i, q->symbol_sz):SRSLTE_CP_LEN_EXT(q->symbol_sz);
memcpy(&q->tmp[q->nof_guards], input, q->nof_re * sizeof(cf_t));
srslte_dft_run_c(&q->fft_plan, q->tmp, &output[cp_len]);
input += q->nof_re;
/* add CP */
memcpy(output, &output[q->symbol_sz], cp_len * sizeof(cf_t));
output += q->symbol_sz + cp_len;
}
}
/* Decide the most likely cell based on the mode */
static void get_cell(srslte_ue_cellsearch_t * q, uint32_t nof_detected_frames, srslte_ue_cellsearch_result_t *found_cell)
{
uint32_t i, j;
bzero(q->mode_counted, nof_detected_frames);
bzero(q->mode_ntimes, sizeof(uint32_t) * nof_detected_frames);
/* First find mode of CELL IDs */
for (i = 0; i < nof_detected_frames; i++) {
uint32_t cnt = 1;
for (j=i+1;j<nof_detected_frames;j++) {
if (q->candidates[j].cell_id == q->candidates[i].cell_id && !q->mode_counted[j]) {
q->mode_counted[j]=1;
cnt++;
}
}
q->mode_ntimes[i] = cnt;
}
uint32_t max_times=0, mode_pos=0;
for (i=0;i<nof_detected_frames;i++) {
if (q->mode_ntimes[i] > max_times) {
max_times = q->mode_ntimes[i];
mode_pos = i;
}
}
found_cell->cell_id = q->candidates[mode_pos].cell_id;
/* Now in all these cell IDs, find most frequent CP */
uint32_t nof_normal = 0;
found_cell->peak = 0;
for (i=0;i<nof_detected_frames;i++) {
if (q->candidates[i].cell_id == found_cell->cell_id) {
if (SRSLTE_CP_ISNORM(q->candidates[i].cp)) {
nof_normal++;
}
}
// average absolute peak value
found_cell->peak += q->candidates[i].peak;
}
found_cell->peak /= nof_detected_frames;
if (nof_normal > q->mode_ntimes[mode_pos]/2) {
found_cell->cp = SRSLTE_CP_NORM;
} else {
found_cell->cp = SRSLTE_CP_EXT;
}
found_cell->mode = (float) q->mode_ntimes[mode_pos]/nof_detected_frames;
// PSR is already averaged so take the last value
found_cell->psr = q->candidates[nof_detected_frames-1].psr;
// CFO is also already averaged
found_cell->cfo = q->candidates[nof_detected_frames-1].cfo;
}
/* 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;
}
}
/* Generates UCI-ACK bits and computes position in q bits */
static int uci_ulsch_interleave_ack_gen(uint32_t ack_q_bit_idx,
uint32_t Qm, uint32_t H_prime_total, uint32_t N_pusch_symbs, srslte_cp_t cp,
srslte_uci_bit_t *ack_bits)
{
const uint32_t ack_column_set_norm[4] = {2, 3, 8, 9};
const uint32_t ack_column_set_ext[4] = {1, 2, 6, 7};
if (H_prime_total/N_pusch_symbs >= 1+ack_q_bit_idx/4) {
uint32_t row = H_prime_total/N_pusch_symbs-1-ack_q_bit_idx/4;
uint32_t colidx = (3*ack_q_bit_idx)%4;
uint32_t col = SRSLTE_CP_ISNORM(cp)?ack_column_set_norm[colidx]:ack_column_set_ext[colidx];
for(uint32_t k=0; k<Qm; k++) {
ack_bits[k].position = row *Qm + (H_prime_total/N_pusch_symbs)*col*Qm + k;
}
return SRSLTE_SUCCESS;
} else {
fprintf(stderr, "Error interleaving UCI-ACK bit idx %d for H_prime_total=%d and N_pusch_symbs=%d\n",
ack_q_bit_idx, H_prime_total, N_pusch_symbs);
return SRSLTE_ERROR;
}
}
// Compute m according to Section 5.4.3 of 36.211
uint32_t srslte_pucch_m(srslte_pucch_cfg_t *cfg, srslte_pucch_format_t format, uint32_t n_pucch, srslte_cp_t cp) {
uint32_t m=0;
switch (format) {
case SRSLTE_PUCCH_FORMAT_1:
case SRSLTE_PUCCH_FORMAT_1A:
case SRSLTE_PUCCH_FORMAT_1B:
m = cfg->n_rb_2;
uint32_t c=SRSLTE_CP_ISNORM(cp)?3:2;
if (n_pucch >= c*cfg->N_cs/cfg->delta_pucch_shift) {
m = (n_pucch-c*cfg->N_cs/cfg->delta_pucch_shift)/(c*SRSLTE_NRE/cfg->delta_pucch_shift)
+cfg->n_rb_2+(uint32_t)ceilf((float) cfg->N_cs/8);
}
break;
case SRSLTE_PUCCH_FORMAT_2:
case SRSLTE_PUCCH_FORMAT_2A:
case SRSLTE_PUCCH_FORMAT_2B:
m = n_pucch/SRSLTE_NRE;
break;
}
return m;
}
/* Inserts UCI-RI bits into the correct positions in the g buffer before interleaving */
static int uci_ulsch_interleave_ri_gen(uint32_t ri_q_bit_idx,
uint32_t Qm, uint32_t H_prime_total, uint32_t N_pusch_symbs, srslte_cp_t cp,
srslte_uci_bit_t *ri_bits)
{
static uint32_t ri_column_set_norm[4] = {1, 4, 7, 10};
static uint32_t ri_column_set_ext[4] = {0, 3, 5, 8};
if (H_prime_total/N_pusch_symbs >= 1+ri_q_bit_idx/4) {
uint32_t row = H_prime_total/N_pusch_symbs-1-ri_q_bit_idx/4;
uint32_t colidx = (3*ri_q_bit_idx)%4;
uint32_t col = SRSLTE_CP_ISNORM(cp)?ri_column_set_norm[colidx]:ri_column_set_ext[colidx];
for(uint32_t k=0; k<Qm; k++) {
ri_bits[k].position = row *Qm + (H_prime_total/N_pusch_symbs)*col*Qm + k;
}
return SRSLTE_SUCCESS;
} else {
fprintf(stderr, "Error interleaving UCI-RI bit idx %d for H_prime_total=%d and N_pusch_symbs=%d\n",
ri_q_bit_idx, H_prime_total, N_pusch_symbs);
return SRSLTE_ERROR;
}
}
/* Shifts the signal after the iFFT or before the FFT.
* Freq_shift is relative to inter-carrier spacing.
* Caution: This function shall not be called during run-time
*/
int srslte_ofdm_set_freq_shift(srslte_ofdm_t *q, float freq_shift) {
q->shift_buffer = srslte_vec_malloc(sizeof(cf_t) * SRSLTE_SF_LEN(q->symbol_sz));
if (!q->shift_buffer) {
perror("malloc");
return -1;
}
cf_t *ptr = q->shift_buffer;
for (uint32_t n=0;n<2;n++) {
for (uint32_t i=0;i<q->nof_symbols;i++) {
uint32_t cplen = SRSLTE_CP_ISNORM(q->cp)?SRSLTE_CP_LEN_NORM(i, q->symbol_sz):SRSLTE_CP_LEN_EXT(q->symbol_sz);
for (uint32_t t=0;t<q->symbol_sz+cplen;t++) {
ptr[t] = cexpf(I*2*M_PI*((float) t-(float)cplen)*freq_shift/q->symbol_sz);
}
ptr += q->symbol_sz+cplen;
}
}
/* Disable DC carrier addition */
srslte_dft_plan_set_dc(&q->fft_plan, false);
q->freq_shift = true;
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);
}
/** Finds the PSS sequence previously defined by a call to srslte_sync_set_N_id_2()
* around the position find_offset in the buffer input.
*
* Returns 1 if the correlation peak exceeds the threshold set by srslte_sync_set_threshold()
* or 0 otherwise. Returns a negative number on error (if N_id_2 has not been set)
*
* The input signal is not modified. Any CFO correction is done in internal buffers
*
* The maximum of the correlation peak is always stored in *peak_position
*/
srslte_sync_find_ret_t srslte_sync_find(srslte_sync_t *q, const cf_t *input, uint32_t find_offset, uint32_t *peak_position)
{
srslte_sync_find_ret_t ret = SRSLTE_SYNC_ERROR;
int peak_pos = 0;
if (!q) {
return SRSLTE_ERROR_INVALID_INPUTS;
}
if (input != NULL &&
srslte_N_id_2_isvalid(q->N_id_2) &&
fft_size_isvalid(q->fft_size))
{
if (peak_position) {
*peak_position = 0;
}
const cf_t *input_ptr = input;
/* First CFO estimation stage is integer.
* Finds max PSS correlation for shifted +1/0/-1 integer versions.
* This should only used once N_id_2 is set
*/
if (q->cfo_i_enable) {
if (cfo_i_estimate(q, input_ptr, find_offset, &peak_pos, &q->cfo_i_value) < 0) {
fprintf(stderr, "Error calling finding PSS sequence at : %d \n", peak_pos);
return SRSLTE_ERROR;
}
// Correct it using precomputed signal and store in buffer (don't modify input signal)
if (q->cfo_i_value != 0) {
srslte_vec_prod_ccc((cf_t*) input_ptr, q->cfo_i_corr[q->cfo_i_value<0?0:1], q->temp, q->frame_size);
INFO("Compensating cfo_i=%d\n", q->cfo_i_value);
input_ptr = q->temp;
}
}
/* Second stage is coarse fractional CFO estimation using CP.
* In case of multi-cell, this can lead to incorrect estimations if CFO from different cells is different
*/
if (q->cfo_cp_enable) {
float cfo_cp = cfo_cp_estimate(q, input_ptr);
if (!q->cfo_cp_is_set) {
q->cfo_cp_mean = cfo_cp;
q->cfo_cp_is_set = true;
} else {
/* compute exponential moving average CFO */
q->cfo_cp_mean = SRSLTE_VEC_EMA(cfo_cp, q->cfo_cp_mean, q->cfo_ema_alpha);
}
INFO("CP-CFO: estimated=%f, mean=%f\n", cfo_cp, q->cfo_cp_mean);
/* Correct CFO with the averaged CFO estimation */
srslte_cfo_correct(&q->cfo_corr_frame, input_ptr, q->temp, -q->cfo_cp_mean / q->fft_size);
input_ptr = q->temp;
}
/* Find maximum of PSS correlation. If Integer CFO is enabled, correlation is already done
*/
if (!q->cfo_i_enable) {
srslte_pss_set_N_id_2(&q->pss, q->N_id_2);
peak_pos = srslte_pss_find_pss(&q->pss, &input_ptr[find_offset], q->threshold>0?&q->peak_value:NULL);
if (peak_pos < 0) {
fprintf(stderr, "Error calling finding PSS sequence at : %d \n", peak_pos);
return SRSLTE_ERROR;
}
}
INFO("PSS: id=%d, peak_pos=%d, peak_value=%f\n", q->N_id_2, peak_pos, q->peak_value);
// Save peak position
if (peak_position) {
*peak_position = (uint32_t) peak_pos;
}
// In case of decimation, this compensates for the constant time shift caused by the low pass filter
if(q->decimate && peak_pos < 0) {
peak_pos = 0 ;//peak_pos + q->decimate*(2);// replace 2 with q->filter_size -2;
}
/* If peak is over threshold, compute CFO and SSS */
if (q->peak_value >= q->threshold || q->threshold == 0) {
if (q->cfo_pss_enable && peak_pos >= q->fft_size) {
// Filter central bands before PSS-based CFO estimation
const cf_t *pss_ptr = &input_ptr[find_offset + peak_pos - q->fft_size];
if (q->pss_filtering_enabled) {
srslte_pss_filter(&q->pss, pss_ptr, q->pss_filt);
pss_ptr = q->pss_filt;
}
// PSS-based CFO estimation
q->cfo_pss = srslte_pss_cfo_compute(&q->pss, pss_ptr);
if (!q->cfo_pss_is_set) {
q->cfo_pss_mean = q->cfo_pss;
q->cfo_pss_is_set = true;
} else if (15000*fabsf(q->cfo_pss) < MAX_CFO_PSS_OFFSET) {
q->cfo_pss_mean = SRSLTE_VEC_EMA(q->cfo_pss, q->cfo_pss_mean, q->cfo_ema_alpha);
}
INFO("PSS-CFO: filter=%s, estimated=%f, mean=%f\n",
q->pss_filtering_enabled?"yes":"no", q->cfo_pss, q->cfo_pss_mean);
}
// If there is enough space for CP and SSS estimation
if (peak_pos + find_offset >= 2 * (q->fft_size + SRSLTE_CP_LEN_EXT(q->fft_size))) {
// If SSS search is enabled, correlate SSS sequence
if (q->sss_en) {
// Set an invalid N_id_1 indicating SSS is yet to be detected
q->N_id_1 = 1000;
int sss_idx = find_offset + 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));
const cf_t *sss_ptr = &input_ptr[sss_idx];
// Correct CFO if detected in PSS
if (q->cfo_pss_enable) {
srslte_cfo_correct(&q->cfo_corr_symbol, sss_ptr, q->sss_filt, -q->cfo_pss_mean / q->fft_size);
// Equalize channel if estimated in PSS
if (q->sss_channel_equalize && q->pss.chest_on_filter && q->pss_filtering_enabled) {
srslte_vec_prod_ccc(&q->sss_filt[q->fft_size/2-SRSLTE_PSS_LEN/2], q->pss.tmp_ce,
&q->sss_filt[q->fft_size/2-SRSLTE_PSS_LEN/2], SRSLTE_PSS_LEN);
}
sss_ptr = q->sss_filt;
}
if (sync_sss_symbol(q, sss_ptr) < 0) {
fprintf(stderr, "Error correlating SSS\n");
return -1;
}
}
// Detect CP length
if (q->detect_cp) {
srslte_sync_set_cp(q, srslte_sync_detect_cp(q, input_ptr, peak_pos + find_offset));
} else {
DEBUG("Not enough room to detect CP length. Peak position: %d\n", peak_pos);
}
ret = SRSLTE_SYNC_FOUND;
} else {
ret = SRSLTE_SYNC_FOUND_NOSPACE;
}
} else {
ret = SRSLTE_SYNC_NOFOUND;
}
DEBUG("SYNC ret=%d N_id_2=%d find_offset=%d frame_len=%d, pos=%d peak=%.2f threshold=%.2f sf_idx=%d, CFO=%.3f kHz\n",
ret, q->N_id_2, find_offset, q->frame_size, peak_pos, q->peak_value,
q->threshold, q->sf_idx, 15*(srslte_sync_get_cfo(q)));
} else if (srslte_N_id_2_isvalid(q->N_id_2)) {
fprintf(stderr, "Must call srslte_sync_set_N_id_2() first!\n");
}
return ret;
}
/**
* Initializes REGs structure.
* Sets all REG indices and initializes PCFICH, PHICH and PDCCH REGs
* Returns 0 if OK, -1 on error
*/
int srslte_regs_init(srslte_regs_t *h, srslte_cell_t cell) {
int ret = SRSLTE_ERROR_INVALID_INPUTS;
uint32_t i, k;
uint32_t j[4], jmax, prb;
uint32_t n[4], vo;
uint32_t max_ctrl_symbols;
if (h != NULL &&
srslte_cell_isvalid(&cell))
{
bzero(h, sizeof(srslte_regs_t));
ret = SRSLTE_ERROR;
max_ctrl_symbols = cell.nof_prb<10?4:3;
vo = cell.id % 3;
h->cell = cell;
h->max_ctrl_symbols = max_ctrl_symbols;
h->cfi_initiated = false;
h->phich_res = cell.phich_resources;
h->phich_len = cell.phich_length;
h->nof_regs = 0;
for (i = 0; i < max_ctrl_symbols; i++) {
n[i] = regs_num_x_symbol(i, h->cell.nof_ports, h->cell.cp);
if (n[i] == -1) {
goto clean_and_exit;
}
h->nof_regs += h->cell.nof_prb * n[i];
}
INFO("Indexing %d REGs. CellId: %d, %d PRB, CP: %s\n", h->nof_regs, h->cell.id, h->cell.nof_prb,
SRSLTE_CP_ISNORM(h->cell.cp)?"Normal":"Extended");
h->regs = malloc(sizeof(srslte_regs_reg_t) * h->nof_regs);
if (!h->regs) {
perror("malloc");
goto clean_and_exit;
}
/* Sort REGs according to PDCCH mapping, beggining from the lowest l index then k */
bzero(j, sizeof(int) * 4);
k = i = prb = jmax = 0;
while (k < h->nof_regs) {
if (n[i] == 3 || (n[i] == 2 && jmax != 1)) {
if (regs_reg_init(&h->regs[k], i, j[i], prb * SRSLTE_NRE, n[i], vo)) {
fprintf(stderr, "Error initializing REGs\n");
goto clean_and_exit;
}
/*DEBUG("Available REG #%3d: l=%d, prb=%d, nreg=%d (k0=%d)\n", k, i, prb, j[i],
h->regs[k].k0);
*/
j[i]++;
k++;
}
i++;
if (i == max_ctrl_symbols) {
i = 0;
jmax++;
}
if (jmax == 3) {
prb++;
bzero(j, sizeof(int) * 4);
jmax = 0;
}
}
if (regs_pcfich_init(h)) {
fprintf(stderr, "Error initializing PCFICH REGs\n");
goto clean_and_exit;
}
if (regs_phich_init(h)) {
fprintf(stderr, "Error initializing PHICH REGs\n");
goto clean_and_exit;
}
if (regs_pdcch_init(h)) {
fprintf(stderr, "Error initializing PDCCH REGs\n");
goto clean_and_exit;
}
ret = SRSLTE_SUCCESS;
}
clean_and_exit:
if (ret != SRSLTE_SUCCESS) {
srslte_regs_free(h);
}
return ret;
}
int main(int argc, char **argv) {
srslte_phich_t phich;
srslte_regs_t regs;
int i, j;
cf_t *ce[SRSLTE_MAX_PORTS];
int nof_re;
cf_t *slot_symbols[SRSLTE_MAX_PORTS];
uint8_t ack[50][SRSLTE_PHICH_NORM_NSEQUENCES], ack_rx;
uint32_t nsf;
float distance;
int cid, max_cid;
uint32_t ngroup, nseq, max_nseq;
parse_args(argc,argv);
max_nseq = SRSLTE_CP_ISNORM(cell.cp)?SRSLTE_PHICH_NORM_NSEQUENCES:SRSLTE_PHICH_EXT_NSEQUENCES;
nof_re = SRSLTE_CP_NORM_NSYMB * cell.nof_prb * SRSLTE_NRE;
/* init memory */
for (i=0;i<SRSLTE_MAX_PORTS;i++) {
ce[i] = malloc(sizeof(cf_t) * nof_re);
if (!ce[i]) {
perror("malloc");
exit(-1);
}
for (j=0;j<nof_re;j++) {
ce[i][j] = 1;
}
slot_symbols[i] = malloc(sizeof(cf_t) * nof_re);
if (!slot_symbols[i]) {
perror("malloc");
exit(-1);
}
}
if (cell.id == 1000) {
cid = 0;
max_cid = 503;
} else {
cid = cell.id;
max_cid = cell.id;
}
while(cid <= max_cid) {
cell.id = cid;
printf("Testing CellID=%d...\n", cid);
if (srslte_regs_init(®s, cell)) {
fprintf(stderr, "Error initiating regs\n");
exit(-1);
}
if (srslte_phich_init(&phich, ®s, cell)) {
fprintf(stderr, "Error creating PBCH object\n");
exit(-1);
}
for (nsf=0;nsf<10;nsf++) {
srslte_phich_reset(&phich, slot_symbols);
/* Transmit all PHICH groups and sequence numbers */
for (ngroup=0;ngroup<srslte_phich_ngroups(&phich);ngroup++) {
for (nseq=0;nseq<max_nseq;nseq++) {
ack[ngroup][nseq] = rand()%2;
srslte_phich_encode(&phich, ack[ngroup][nseq], ngroup, nseq, nsf, slot_symbols);
}
}
/* combine outputs */
for (i=1;i<cell.nof_ports;i++) {
for (j=0;j<nof_re;j++) {
slot_symbols[0][j] += slot_symbols[i][j];
}
}
/* Receive all PHICH groups and sequence numbers */
for (ngroup=0;ngroup<srslte_phich_ngroups(&phich);ngroup++) {
for (nseq=0;nseq<max_nseq;nseq++) {
if (srslte_phich_decode(&phich, slot_symbols[0], ce, 0, ngroup, nseq, nsf, &ack_rx, &distance)<0) {
printf("Error decoding ACK\n");
exit(-1);
}
INFO("%d/%d, ack_tx: %d, ack_rx: %d, ns: %d, distance: %f\n",
ngroup, nseq, ack[ngroup][nseq], ack_rx, nsf, distance);
if (ack[ngroup][nseq] != ack_rx) {
printf("Invalid received ACK: %d!=%d\n", ack[ngroup][nseq], ack_rx);
exit(-1);
}
if (distance < 1.5) {
printf("Error\n");
exit(-1);
}
}
}
}
srslte_phich_free(&phich);
srslte_regs_free(®s);
cid++;
}
for (i=0;i<SRSLTE_MAX_PORTS;i++) {
free(ce[i]);
free(slot_symbols[i]);
}
printf("OK\n");
exit(0);
}
/**
* 36.211 6.6.1
*/
int srslte_sequence_pbch(srslte_sequence_t *seq, srslte_cp_t cp, uint32_t cell_id) {
bzero(seq, sizeof(srslte_sequence_t));
return srslte_sequence_LTE_pr(seq, SRSLTE_CP_ISNORM(cp)?1920:1728, cell_id);
}
