Files
openairinterface5g/openair1/PHY/NR_REFSIG/nr_gold_ue.c
T
Sakthivel Velumani 043da0c440 NR UE scan for SSB within current bandwidth
Till this commit, the UE gets the position of SSB in frequency from
command line and does the syncronization by locating the SSB in time. It
does this by generating a PSS time signal during initialization with the
SSB offset given via command line. Then PSS detection is done by
correlation.

In this commit, the UE computes a list of GSCN in the current NR band
that falls within the current bandwidth for the set center frequency.
For each GSCN in the list, the UE starts a thread and performs the
following:
1. Generate PSS time signal with SSB offset for current GSCN.
2. Detect PSS, SSS and decode PBCH (this step remains the same).
After all threads finishes, the results are collected.

For now, only the first detected PBCH is used to proceed further. So
this PBCH is indicated to MAC and UE exits initial sync.

Future work: The cell search can be standalone feature where the UE
could scan for SSB in the entire NR band. This would require changing
radio's frequency on the fly as the UE's bandwidth would not cover an
entire NR band. The cell detection can futher be imporved by looking
for SIB1 for each decoded PBCH.
2024-05-30 10:20:45 -04:00

174 lines
6.0 KiB
C

/*
* Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The OpenAirInterface Software Alliance licenses this file to You under
* the OAI Public License, Version 1.1 (the "License"); you may not use this file
* except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.openairinterface.org/?page_id=698
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*-------------------------------------------------------------------------------
* For more information about the OpenAirInterface (OAI) Software Alliance:
* contact@openairinterface.org
*/
#include "refsig_defs_ue.h"
void nr_gold_pbch(uint32_t nr_gold_pbch[2][64][NR_PBCH_DMRS_LENGTH_DWORD], int Nid, int Lmax)
{
unsigned int n = 0, x1 = 0, x2 = 0;
unsigned int i_ssb, i_ssb2;
unsigned char l, n_hf, N_hf;
uint8_t reset;
N_hf = (Lmax == 4)? 2:1;
for (n_hf = 0; n_hf < N_hf; n_hf++) {
for (l = 0; l < Lmax ; l++) {
i_ssb = l & (Lmax-1);
i_ssb2 = i_ssb + (n_hf<<2);
reset = 1;
x2 = (1<<11) * (i_ssb2 + 1) * ((Nid>>2) + 1) + (1<<6) * (i_ssb2 + 1) + (Nid&3);
for (n=0; n<NR_PBCH_DMRS_LENGTH_DWORD; n++) {
nr_gold_pbch[n_hf][l][n] = lte_gold_generic(&x1, &x2, reset);
reset = 0;
}
}
}
}
void nr_gold_pdcch(PHY_VARS_NR_UE* ue,
unsigned short nid)
{
int pdcch_dmrs_init_length = (((ue->frame_parms.N_RB_DL << 1) * 3) >> 5) + 1;
for (int ns = 0; ns < ue->frame_parms.slots_per_frame; ns++) {
for (int l = 0; l < ue->frame_parms.symbols_per_slot; l++) {
uint8_t reset = 1;
uint64_t x2tmp0 = ((ue->frame_parms.symbols_per_slot * ns + l + 1) * ((nid << 1) + 1));
x2tmp0 <<= 17;
x2tmp0 += (nid << 1);
uint32_t x1 = 0;
uint32_t x2 = x2tmp0 % (1U << 31); //cinit
LOG_D(PHY,"PDCCH DMRS slot %d, symb %d, Nid %d, x2 %x\n", ns, l, nid, x2);
for (int n = 0; n < pdcch_dmrs_init_length; n++) {
ue->nr_gold_pdcch[0][ns][l][n] = lte_gold_generic(&x1, &x2, reset);
reset = 0;
}
}
}
}
void nr_gold_pdsch(PHY_VARS_NR_UE* ue,
int nscid,
uint32_t nid)
{
int pdsch_dmrs_init_length = ((ue->frame_parms.N_RB_DL * 12) >> 5) + 1;
for (int ns=0; ns<ue->frame_parms.slots_per_frame; ns++) {
for (int l=0; l<ue->frame_parms.symbols_per_slot; l++) {
uint8_t reset = 1;
uint64_t x2tmp0 = ((ue->frame_parms.symbols_per_slot * ns + l + 1) * ((nid << 1) + 1)) << 17;
uint32_t x1 = 0;
uint32_t x2 = (x2tmp0 + (nid << 1) + nscid) % (1U << 31); //cinit
LOG_D(PHY,"UE DMRS slot %d, symb %d, nscid %d, x2 %x\n", ns, l, nscid, x2);
for (int n = 0; n < pdsch_dmrs_init_length; n++) {
ue->nr_gold_pdsch[0][ns][l][nscid][n] = lte_gold_generic(&x1, &x2, reset);
reset = 0;
}
}
}
}
void nr_init_pusch_dmrs(PHY_VARS_NR_UE* ue, uint16_t N_n_scid, uint8_t n_scid)
{
NR_DL_FRAME_PARMS *fp = &ue->frame_parms;
uint32_t ****pusch_dmrs = ue->nr_gold_pusch_dmrs;
int pusch_dmrs_init_length = ((fp->N_RB_UL * 12) >> 5) + 1;
for (int slot = 0; slot < fp->slots_per_frame; slot++) {
for (int symb = 0; symb < fp->symbols_per_slot; symb++) {
int reset = 1;
uint32_t x1 = 0;
uint64_t t_x2 = ((1UL << 17) * (fp->symbols_per_slot*slot + symb + 1) * ((N_n_scid << 1) + 1) + ((N_n_scid << 1) + n_scid));
uint32_t x2 = t_x2 % (1U << 31);
LOG_D(PHY,"DMRS slot %d, symb %d, N_n_scid %d, n_scid %d, x2 %x\n", slot, symb, N_n_scid, n_scid, x2);
for (int n = 0; n < pusch_dmrs_init_length; n++) {
pusch_dmrs[slot][symb][n_scid][n] = lte_gold_generic(&x1, &x2, reset);
reset = 0;
}
}
}
}
void init_nr_gold_prs(PHY_VARS_NR_UE* ue)
{
unsigned int x1 = 0, x2 = 0;
uint16_t Nid;
NR_DL_FRAME_PARMS *fp = &ue->frame_parms;
uint8_t reset;
uint8_t slotNum, symNum, gnb, rsc;
for(gnb = 0; gnb < ue->prs_active_gNBs; gnb++) {
for(rsc = 0; rsc < ue->prs_vars[gnb]->NumPRSResources; rsc++) {
Nid = ue->prs_vars[gnb]->prs_resource[rsc].prs_cfg.NPRSID; // seed value
LOG_I(PHY,"Initialised NR-PRS sequence with PRS_ID %3d for resource %d\n",Nid, rsc);
for (slotNum = 0; slotNum < fp->slots_per_frame; slotNum++) {
for (symNum = 0; symNum < fp->symbols_per_slot ; symNum++) {
reset = 1;
// initial x2 for prs as ts138.211
uint32_t c_init1, c_init2, c_init3;
uint32_t pow22=1<<22;
uint32_t pow10=1<<10;
c_init1 = pow22*ceil(Nid/1024);
c_init2 = pow10*(slotNum+symNum+1)*(2*(Nid%1024)+1);
c_init3 = Nid%1024;
x2 = c_init1 + c_init2 + c_init3;
for (uint8_t n=0; n<NR_MAX_PRS_INIT_LENGTH_DWORD; n++) {
ue->nr_gold_prs[gnb][rsc][slotNum][symNum][n] = lte_gold_generic(&x1, &x2, reset);
reset = 0;
//printf("%d \n",gNB->nr_gold_prs[slotNum][symNum][n]);
}
}
}
} // for rsc
} // for gnb
}
void sl_init_psbch_dmrs_gold_sequences(PHY_VARS_NR_UE *UE)
{
unsigned int x1, x2;
uint16_t slss_id;
uint8_t reset;
for (slss_id = 0; slss_id < SL_NR_NUM_SLSS_IDs; slss_id++) {
reset = 1;
x2 = slss_id;
#ifdef SL_DEBUG_INIT
printf("\nPSBCH DMRS GOLD SEQ for SLSSID :%d :\n", slss_id);
#endif
for (uint8_t n = 0; n < SL_NR_NUM_PSBCH_DMRS_RE_DWORD; n++) {
UE->SL_UE_PHY_PARAMS.init_params.psbch_dmrs_gold_sequences[slss_id][n] = lte_gold_generic(&x1, &x2, reset);
reset = 0;
#ifdef SL_DEBUG_INIT_DATA
printf("%x\n", SL_UE_INIT_PARAMS.sl_psbch_dmrs_gold_sequences[slss_id][n]);
#endif
}
}
}