PentHertz
/
srsLTE
mirror of https://github.com/PentHertz/srsLTE.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

srsLTE: DL channel estimator compensates channel delay

This commit is contained in:
Xavier Arteaga 2020-01-27 15:04:04 +01:00 committed by Xavier Arteaga
parent 17f9ff326b
commit c0b611dd0d
1 changed files with 19 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
lib/src/phy/ch_estimation/chest_dl.c
View File

@ -705,6 +705,25 @@ static int estimate_port(srslte_chest_dl_t* q,
q->sync_err[rxant_id][port_id] = NAN;
}
// Correct time synchronization error if estimated
if (isnormal(q->sync_err[rxant_id][port_id])) {
uint32_t nsymb = SRSLTE_CP_NSYMB(q->cell.cp) * SRSLTE_NOF_SLOTS_PER_SF;
float cfo = q->sync_err[rxant_id][port_id] / (float)srslte_symbol_sz(q->cell.nof_prb);
uint32_t nre = SRSLTE_NRE * q->cell.nof_prb;
for (uint32_t i = 0; i < nsymb; i++) {
cf_t* ptr = &input[i * nre];
srslte_vec_apply_cfo(ptr, cfo, ptr, nre);
}
/* Get references from the input signal */
srslte_refsignal_cs_get_sf(&q->csr_refs, sf, port_id, input, q->pilot_recv_signal);
/* Use the known CSR signal to compute Least-squares estimates */
srslte_vec_prod_conj_ccc(
q->pilot_recv_signal, q->csr_refs.pilots[port_id / 2][sf->tti % 10], q->pilot_estimates, npilots);
}
/* Compute RSRP for the channel estimates in this port */
if (cfg->rsrp_neighbour) {
double energy = cabsf(srslte_vec_acc_cc(q->pilot_estimates, npilots) / npilots);