int srslte_ue_dl_decode_phich(srslte_ue_dl_t* q,
srslte_dl_sf_cfg_t* sf,
srslte_ue_dl_cfg_t* cfg,
srslte_phich_grant_t* grant,
srslte_phich_res_t* result)
{
srslte_phich_resource_t n_phich;
uint32_t sf_idx = sf->tti % 10;
set_mi_value(q, sf, cfg);
srslte_phich_calc(&q->phich, grant, &n_phich);
INFO("Decoding PHICH sf_idx=%d, n_prb_lowest=%d, n_dmrs=%d, I_phich=%d, n_group=%d, n_seq=%d, Ngroups=%d, Nsf=%d\n",
sf_idx,
grant->n_prb_lowest,
grant->n_dmrs,
grant->I_phich,
n_phich.ngroup,
n_phich.nseq,
srslte_phich_ngroups(&q->phich),
srslte_phich_nsf(&q->phich));
if (!srslte_phich_decode(&q->phich, sf, &q->chest_res, n_phich, q->sf_symbols, result)) {
INFO("Decoded PHICH %d with distance %f\n", result->ack_value, result->distance);
return 0;
} else {
ERROR("Error decoding PHICH\n");
return -1;
}
}
/* Computes n_group and n_seq according to Section 9.1.2 in 36.213 and calls phich processing function */
bool srslte_ue_dl_decode_phich(srslte_ue_dl_t *q, uint32_t sf_idx, uint32_t n_prb_lowest, uint32_t n_dmrs)
{
uint8_t ack_bit;
float distance;
uint32_t Ngroups = srslte_phich_ngroups(&q->phich);
uint32_t ngroup = (n_prb_lowest+n_dmrs)%Ngroups;
uint32_t nseq = ((n_prb_lowest/Ngroups)+n_dmrs)%(2*srslte_phich_nsf(&q->phich));
DEBUG("Decoding PHICH sf_idx=%d, n_prb_lowest=%d, n_dmrs=%d, n_group=%d, n_seq=%d\n",
sf_idx, n_prb_lowest, n_dmrs, ngroup, nseq);
if (!srslte_phich_decode(&q->phich, q->sf_symbols, q->ce, 0, ngroup, nseq, sf_idx, &ack_bit, &distance)) {
INFO("Decoded PHICH %d with distance %f\n", ack_bit, distance);
} else {
fprintf(stderr, "Error decoding PHICH\n");
return false;
}
if (ack_bit && distance > 1.5) {
return true;
} else {
return false;
}
}
bool srslte_ue_dl_decode_phich(srslte_ue_dl_t *q, uint32_t sf_idx, uint32_t n_prb_lowest, uint32_t n_dmrs)
{
uint8_t ack_bit;
float distance;
uint32_t ngroup, nseq;
srslte_phich_calc(&q->phich, n_prb_lowest, n_dmrs, &ngroup, &nseq);
INFO("Decoding PHICH sf_idx=%d, n_prb_lowest=%d, n_dmrs=%d, n_group=%d, n_seq=%d, Ngroups=%d, Nsf=%d\n",
sf_idx, n_prb_lowest, n_dmrs, ngroup, nseq,
srslte_phich_ngroups(&q->phich), srslte_phich_nsf(&q->phich));
if (!srslte_phich_decode(&q->phich, q->sf_symbols_m, q->ce_m, 0, ngroup, nseq, sf_idx, &ack_bit, &distance)) {
q->last_phich_corr = distance;
INFO("Decoded PHICH %d with distance %f\n", ack_bit, distance);
} else {
fprintf(stderr, "Error decoding PHICH\n");
return false;
}
if (ack_bit) {
return true;
} else {
return false;
}
}
