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srsLTE
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Use Format1A when using CA and 15 PRB due to DCI size ambiguity

This commit is contained in:
Ismael Gomez 2020-09-01 15:17:15 +02:00 committed by Xavier Arteaga
parent 3ee15191e7
commit 38e2ffe414
5 changed files with 43 additions and 9 deletions
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4
lib/src/phy/ue/ue_dl.c
View File

@ -497,16 +497,12 @@ static int dci_blind_search(srslte_ue_dl_t* q,
* information fields in the common and UE-specific search spaces on the primary cell, is required to assume
* that only the PDCCH in the common search space is transmitted by the primary cell.
*/
INFO("checking if msg=%d, ncce=%d belongs to common\n", nof_dci, dci_msg[nof_dci].location.ncce);
// Find a matching ncce in the common SS
if (srslte_location_find_ncce(q->current_ss_common[MI_IDX(sf_idx)][cfi - 1].loc,
q->current_ss_common[MI_IDX(sf_idx)][cfi - 1].nof_locations,
dci_msg[nof_dci].location.ncce)) {
srslte_dci_cfg_t cfg = *dci_cfg;
srslte_dci_cfg_set_common_ss(&cfg);
INFO("checking if size of msg (%d) is equal to size of format1a (%d)\n",
dci_msg[nof_dci].nof_bits,
srslte_dci_format_sizeof(&q->cell, sf, &cfg, SRSLTE_DCI_FORMAT1A));
// if the payload size is the same that it would have in the common SS (only Format0/1A is allowed there)
if (dci_msg[nof_dci].nof_bits == srslte_dci_format_sizeof(&q->cell, sf, &cfg, SRSLTE_DCI_FORMAT1A)) {
// assume that only the PDDCH is transmitted, therefore update the format to 0/1A

1
srsenb/hdr/stack/mac/scheduler_common.h
View File

@ -85,6 +85,7 @@ struct prb_interval;
struct rbg_interval : public srslte::interval<uint32_t> {
using interval::interval;
static rbg_interval prbs_to_rbgs(const prb_interval& prbs, uint32_t P);
static rbg_interval rbgmask_to_rbgs(const rbgmask_t& mask);
};
//! Struct to express a {min,...,max} range of PRBs

2
srsenb/src/phy/cc_worker.cc
View File

@ -483,7 +483,7 @@ int cc_worker::encode_pdcch_dl(stack_interface_phy_lte::dl_sched_grant_t* grants
if (SRSLTE_RNTI_ISUSER(grants[i].dci.rnti) && grants[i].dci.format == SRSLTE_DCI_FORMAT1A) {
if (srslte_enb_dl_location_is_common_ncce(&enb_dl, grants[i].dci.location.ncce) &&
grants[i].dci.format == SRSLTE_DCI_FORMAT1A && phy->ue_db.is_pcell(grants[i].dci.rnti, cc_idx)) {
phy->ue_db.is_pcell(grants[i].dci.rnti, cc_idx)) {
srslte_dci_cfg_set_common_ss(&dci_cfg);
}
}

21
srsenb/src/stack/mac/scheduler.cc
View File

@ -460,6 +460,27 @@ prb_interval prb_interval::rbgs_to_prbs(const rbg_interval& rbgs, uint32_t P)
return prb_interval{rbgs.start() * P, rbgs.stop() * P};
}
rbg_interval rbg_interval::rbgmask_to_rbgs(const rbgmask_t& mask)
{
int rb_start = -1;
for (uint32_t i = 0; i < mask.size(); i++) {
if (rb_start == -1) {
if (mask.test(i)) {
rb_start = i;
}
} else {
if (!mask.test(i)) {
return rbg_interval(rb_start, i);
}
}
}
if (rb_start != -1) {
return rbg_interval(rb_start, mask.size());
} else {
return rbg_interval();
}
}
prb_interval prb_interval::riv_to_prbs(uint32_t riv, uint32_t nof_prbs, int nof_vrbs)
{
if (nof_vrbs < 0) {

24
srsenb/src/stack/mac/scheduler_ue.cc
View File

@ -479,8 +479,26 @@ int sched_ue::generate_format1(uint32_t pid,
int mcs = 0;
int tbs = 0;
dci->alloc_type = SRSLTE_RA_ALLOC_TYPE0;
dci->type0_alloc.rbg_bitmask = (uint32_t)user_mask.to_uint64();
// If the size of Format1 and Format1A is ambiguous in the common SS, use Format1A since the UE assumes
// Common SS when spaces collide
if (cell.nof_prb == 15 && carriers.size() > 1) {
dci->alloc_type = SRSLTE_RA_ALLOC_TYPE2;
dci->type2_alloc.mode = srslte_ra_type2_t::SRSLTE_RA_TYPE2_LOC;
rbg_interval rbg_int = rbg_interval::rbgmask_to_rbgs(user_mask);
uint32_t P = srslte_ra_type0_P(15);
prb_interval prb_int = prb_interval::rbgs_to_prbs(rbg_int, P);
dci->type2_alloc.riv =
srslte_ra_type2_to_riv(SRSLTE_MIN(prb_int.length(), cell.nof_prb), prb_int.start(), cell.nof_prb);
dci->format = SRSLTE_DCI_FORMAT1A;
if (prb_int.length() != P * user_mask.count()) {
// This happens if Type0 was using distributed allocation
Warning("SCHED: Can't use distributed RA due to DCI size ambiguity\n");
}
} else {
dci->alloc_type = SRSLTE_RA_ALLOC_TYPE0;
dci->type0_alloc.rbg_bitmask = (uint32_t)user_mask.to_uint64();
dci->format = SRSLTE_DCI_FORMAT1;
}
if (h->is_empty(0)) {
auto ret = allocate_new_dl_mac_pdu(data, h, user_mask, tti_tx_dl, ue_cc_idx, cfi, 0, "1");
@ -503,8 +521,6 @@ int sched_ue::generate_format1(uint32_t pid,
next_tpc_pucch = 1;
data->tbs[0] = (uint32_t)tbs;
data->tbs[1] = 0;
dci->format = SRSLTE_DCI_FORMAT1;
}
return tbs;
}