yigid/openairinterface5g
1
0
Fork 0
mirror of https://gitlab.eurecom.fr/oai/openairinterface5g.git synced 2026-07-13 04:30:28 +00:00
Code Issues Packages Projects Releases Wiki Activity

feat(phy): Allow per-repetition PRACH reception

Browse Source 
Signed-off-by: Bartosz Podrygajlo <bartosz.podrygajlo@openairinterface.org>
This commit is contained in:
Bartosz Podrygajlo
2026-06-18 14:37:13 +02:00
parent df5a9facbe
commit 82c3c04018
2 changed files with 259 additions and 246 deletions
Download Patch File Download Diff File Expand all files Collapse all files

498
openair1/PHY/NR_TRANSPORT/nr_prach.c
View File

@@ -12,6 +12,202 @@
#include "PHY/NR_TRANSPORT/nr_transport_common_proto.h"
#include "openair1/PHY/NR_TRANSPORT/nr_prach.h"
typedef struct {
int reps;
int Ncp;
int dftlen;
int N_ZC;
int k;
dft_size_idx_t dftsize;
int sample_offset_slot;
} prach_ru_params_t;
static prach_ru_params_t get_prach_ru_params(prach_item_t *p,
int prachStartSymbol,
NR_DL_FRAME_PARMS *fp)
{
prach_ru_params_t par = {0};
const int sum = fp->ofdm_symbol_size + fp->nb_prefix_samples;
const int sum0 = fp->ofdm_symbol_size + fp->nb_prefix_samples0;
if (prachStartSymbol == 0) {
par.sample_offset_slot = 0;
} else if (fp->slots_per_subframe == 1) {
if (prachStartSymbol <= 7)
par.sample_offset_slot = sum * (prachStartSymbol - 1) + sum0;
else
par.sample_offset_slot = sum * (prachStartSymbol - 2) + sum0 * 2;
} else {
if (!(p->slot % (fp->slots_per_subframe / 2)))
par.sample_offset_slot = sum * (prachStartSymbol - 1) + sum0;
else
par.sample_offset_slot = sum * prachStartSymbol;
}
int mu = p->numerology_index;
if (p->prach_sequence_length == 0) {
switch (p->pdu.prach_format) {
case 0:
par.reps = 1;
par.Ncp = 3168;
par.dftlen = 24576;
break;
case 1:
par.reps = 2;
par.Ncp = 21024;
par.dftlen = 24576;
break;
case 2:
par.reps = 4;
par.Ncp = 4688;
par.dftlen = 24576;
break;
case 3:
par.reps = 4;
par.Ncp = 3168;
par.dftlen = 6144;
break;
default:
AssertFatal(1 == 0, "Illegal prach format %d for length 839\n", p->pdu.prach_format);
break;
}
} else {
switch (p->pdu.prach_format) {
case 4: // A1
par.reps = 2;
par.Ncp = 288 >> mu;
break;
case 5: // A2
par.reps = 4;
par.Ncp = 576 >> mu;
break;
case 6: // A3
par.reps = 6;
par.Ncp = 864 >> mu;
break;
case 7: // B1
par.reps = 2;
par.Ncp = 216 >> mu;
break;
case 8: // B4
par.reps = 12;
par.Ncp = 936 >> mu;
break;
case 9: // C0
par.reps = 1;
par.Ncp = 1240 >> mu;
break;
case 10: // C2
par.reps = 4;
par.Ncp = 2048 >> mu;
break;
default:
AssertFatal(1 == 0, "unknown prach format %x\n", p->pdu.prach_format);
break;
}
par.dftlen = 2048 >> mu;
}
if (p->numerology_index == 0) {
if (prachStartSymbol == 0 || prachStartSymbol == 7)
par.Ncp += 16;
} else {
if (p->slot % (fp->slots_per_subframe / 2) == 0 && prachStartSymbol == 0)
par.Ncp += 16;
}
switch(fp->samples_per_subframe) {
case 7680:
// 5 MHz @ 7.68 Ms/s
par.Ncp >>= 2;
par.dftlen >>= 2;
break;
case 15360:
// 10, 15 MHz @ 15.36 Ms/s
par.Ncp >>= 1;
par.dftlen >>= 1;
break;
case 23040:
// 20 MHz @ 23.04 Ms/s
par.Ncp = (par.Ncp * 3) / 4;
par.dftlen = (par.dftlen * 3) / 4;
break;
case 30720:
// 20, 25, 30 MHz @ 30.72 Ms/s
break;
case 46080:
// 40 MHz @ 46.08 Ms/s
par.Ncp = (par.Ncp*3)/2;
par.dftlen = (par.dftlen*3)/2;
break;
case 61440:
// 40, 50, 60 MHz @ 61.44 Ms/s
par.Ncp <<= 1;
par.dftlen <<= 1;
break;
case 92160:
// 50, 60, 70, 80, 90 MHz @ 92.16 Ms/s
par.Ncp *= 3;
par.dftlen *= 3;
break;
case 122880:
// 70, 80, 90, 100 MHz @ 122.88 Ms/s
par.Ncp <<= 2;
par.dftlen <<= 2;
break;
case 184320:
// 100 MHz @ 184.32 Ms/s
par.Ncp = par.Ncp*6;
par.dftlen = par.dftlen*6;
break;
case 245760:
// 200 MHz @ 245.76 Ms/s
par.Ncp <<= 3;
par.dftlen <<= 3;
break;
default:
AssertFatal(1==0,"sample rate %f MHz not supported for numerology %d\n", fp->samples_per_subframe / 1000.0, mu);
}
par.dftsize = get_dft(par.dftlen);
par.N_ZC = (p->prach_sequence_length == 0) ? 839 : 139;
const unsigned int K = get_prach_K(p->prach_sequence_length, p->pdu.prach_format, p->numerology_index, p->mu);
const uint8_t kbar = get_PRACH_k_bar(p->mu, p->numerology_index);
int n_ra_prb = p->msg1_frequencystart;
int k = (12*n_ra_prb) - 6*fp->N_RB_UL;
if (k<0) k+=(fp->ofdm_symbol_size);
k*=K;
k+=kbar;
par.k = k;
return par;
}
void init_nr_prach(PHY_VARS_gNB *gNB)
{
int num_prach = 16;
@@ -114,6 +310,38 @@ void nr_schedule_rx_prach(PHY_VARS_gNB *gNB, int SFN, int Slot, nfapi_nr_prach_p
LOG_W(NR_PHY, "%4d.%2d PRACH occ queue is full: dropping PRACH request\n", SFN, Slot);
}
static void rx_nr_prach_ru_internal_rep(prach_item_t *p,
int ant_offset,
int32_t **rxdata,
NR_DL_FRAME_PARMS *fp,
int N_TA_offset,
int rep,
const prach_ru_params_t *params,
c16_t (*rxsigF)[NR_PRACH_SEQ_LEN_L])
{
AssertFatal(rep >= 0 && rep < params->reps, "rep %d is out of range (reps = %d)\n", rep, params->reps);
int slot2 = p->prach_sequence_length ? p->slot : p->slot;
int sample_offset = get_samples_slot_timestamp(fp, slot2) + params->sample_offset_slot - N_TA_offset + params->Ncp + rep * params->dftlen;
for (int aa = 0; aa < p->nb_rx; aa++) {
int idx = ant_offset + aa;
c16_t *prach2 = (c16_t *)&rxdata[idx][sample_offset];
// do DFT for the specific repetition
c16_t tmp[params->dftlen] __attribute__((aligned(32)));
dft(params->dftsize, (int16_t *)prach2, (int16_t *)tmp, 1);
// Coherent combining of PRACH repetitions (assumes channel does not change, to be revisted for "long" PRACH)
LOG_D(PHY, "Doing PRACH combining of repetition %d/%d N_ZC %d\n", rep, params->reps, params->N_ZC);
int k2 = params->k;
for (int j = 0; j < params->N_ZC; j++, k2++) {
if (k2 == params->dftlen)
k2 = 0;
rxsigF[aa][j] = c16add(rxsigF[aa][j], tmp[k2]);
}
}
}
static void rx_nr_prach_ru_internal(prach_item_t *p,
int prachStartSymbol,
int prachOccasion,
@@ -122,229 +350,9 @@ static void rx_nr_prach_ru_internal(prach_item_t *p,
int N_TA_offset,
bool das)
{
int sample_offset_slot;
const int sum = fp->ofdm_symbol_size + fp->nb_prefix_samples;
const int sum0 = fp->ofdm_symbol_size + fp->nb_prefix_samples0;
if (prachStartSymbol == 0) {
sample_offset_slot = 0;
} else if (fp->slots_per_subframe == 1) {
if (prachStartSymbol <= 7)
sample_offset_slot = sum * (prachStartSymbol - 1) + sum0;
else
sample_offset_slot = sum * (prachStartSymbol - 2) + sum0 * 2;
} else {
if (!(p->slot % (fp->slots_per_subframe / 2)))
sample_offset_slot = sum * (prachStartSymbol - 1) + sum0;
else
sample_offset_slot = sum * prachStartSymbol;
}
LOG_D(PHY,
"frame %d, slot %d: doing rx_nr_prach_ru for format %d, numRA %d, prachStartSymbol %d, prachOccasion %d\n",
p->frame,
p->slot,
p->pdu.prach_format,
p->pdu.num_ra,
prachStartSymbol,
prachOccasion);
int reps;
int Ncp;
int dftlen;
int mu = p->numerology_index;
if (p->prach_sequence_length == 0) {
LOG_D(PHY,
"PRACH in %d.%d, format %d, msg1_frequencyStart %d\n",
p->frame,
p->slot,
p->pdu.prach_format,
p->msg1_frequencystart);
switch (p->pdu.prach_format) {
case 0:
reps = 1;
Ncp = 3168;
dftlen = 24576;
break;
case 1:
reps = 2;
Ncp = 21024;
dftlen = 24576;
break;
case 2:
reps = 4;
Ncp = 4688;
dftlen = 24576;
break;
case 3:
reps = 4;
Ncp = 3168;
dftlen = 6144;
break;
default:
AssertFatal(1 == 0, "Illegal prach format %d for length 839\n", p->pdu.prach_format);
break;
}
} else {
LOG_D(PHY,
"PRACH in %d.%d, format %s, msg1_frequencyStart %d,startSymbol %d\n",
p->frame,
p->slot,
prachfmt[p->pdu.prach_format],
p->msg1_frequencystart,
prachStartSymbol);
switch (p->pdu.prach_format) {
case 4: // A1
reps = 2;
Ncp = 288 >> mu;
break;
case 5: // A2
reps = 4;
Ncp = 576 >> mu;
break;
case 6: // A3
reps = 6;
Ncp = 864 >> mu;
break;
case 7: // B1
reps = 2;
Ncp = 216 >> mu;
break;
/*
// B2 and B3 do not exist in FAPI
case 4: //B2
reps = 4;
Ncp = 360 >> mu;
break;
case 5: //B3
reps = 6;
Ncp = 504 >> mu;
break;
*/
case 8: // B4
reps = 12;
Ncp = 936 >> mu;
break;
case 9: // C0
reps = 1;
Ncp = 1240 >> mu;
break;
case 10: // C2
reps = 4;
Ncp = 2048 >> mu;
break;
default:
AssertFatal(1 == 0, "unknown prach format %x\n", p->pdu.prach_format);
break;
}
dftlen = 2048 >> mu;
}
//actually what we should be checking here is how often the current prach crosses a 0.5ms boundary.
//I am not quite sure for which paramter set this would be the case,
//so I will ignore it for now and just check if the prach starts on a 0.5ms boundary
if (p->numerology_index == 0) {
if (prachStartSymbol == 0 || prachStartSymbol == 7)
Ncp += 16;
} else {
if (p->slot % (fp->slots_per_subframe / 2) == 0 && prachStartSymbol == 0)
Ncp += 16;
}
switch(fp->samples_per_subframe) {
case 7680:
// 5 MHz @ 7.68 Ms/s
Ncp >>= 2;
dftlen >>= 2;
break;
case 15360:
// 10, 15 MHz @ 15.36 Ms/s
Ncp >>= 1;
dftlen >>= 1;
break;
case 23040:
// 20 MHz @ 23.04 Ms/s
Ncp = (Ncp * 3) / 4;
dftlen = (dftlen * 3) / 4;
break;
case 30720:
// 20, 25, 30 MHz @ 30.72 Ms/s
break;
case 46080:
// 40 MHz @ 46.08 Ms/s
Ncp = (Ncp*3)/2;
dftlen = (dftlen*3)/2;
break;
case 61440:
// 40, 50, 60 MHz @ 61.44 Ms/s
Ncp <<= 1;
dftlen <<= 1;
break;
case 92160:
// 50, 60, 70, 80, 90 MHz @ 92.16 Ms/s
Ncp *= 3;
dftlen *= 3;
break;
case 122880:
// 70, 80, 90, 100 MHz @ 122.88 Ms/s
Ncp <<= 2;
dftlen <<= 2;
break;
case 184320:
// 100 MHz @ 184.32 Ms/s
Ncp = Ncp*6;
dftlen = dftlen*6;
break;
case 245760:
// 200 MHz @ 245.76 Ms/s
Ncp <<= 3;
dftlen <<= 3;
break;
default:
AssertFatal(1==0,"sample rate %f MHz not supported for numerology %d\n", fp->samples_per_subframe / 1000.0, mu);
}
const dft_size_idx_t dftsize = get_dft(dftlen);
// Do forward transform
if (LOG_DEBUGFLAG(DEBUG_PRACH)) {
LOG_D(PHY, "rx_prach: Doing PRACH FFT for nb_rx:%d Ncp:%d dftlen:%d\n", p->nb_rx, Ncp, dftlen);
}
const unsigned int K = get_prach_K(p->prach_sequence_length, p->pdu.prach_format, p->numerology_index, p->mu);
const uint8_t kbar = get_PRACH_k_bar(p->mu, p->numerology_index);
int n_ra_prb = p->msg1_frequencystart;
int k = (12*n_ra_prb) - 6*fp->N_RB_UL;
int N_ZC = (p->prach_sequence_length == 0) ? 839 : 139;
if (k<0) k+=(fp->ofdm_symbol_size);
k*=K;
k+=kbar;
prach_ru_params_t params = get_prach_ru_params(p, prachStartSymbol, fp);
c16_t rxsigF_tmp[p->nb_rx][NR_PRACH_SEQ_LEN_L];
memset(rxsigF_tmp, 0, sizeof(rxsigF_tmp));
const uint8_t num_beams = p->pdu.beamforming.dig_bf_interface;
// When more than one beams, then each occasion is on one beam
@@ -353,36 +361,20 @@ static void rx_nr_prach_ru_internal(prach_item_t *p,
AssertFatal(prachOccasion < num_beams, "Num of PRACH Occasions must be same as number of beams in beamforming mode\n");
ant_offset = prachOccasion * p->nb_rx;
}
// TODO: Remove assumption of contiguous ports after DAS is properly handled in beamforming
uint16_t ant_start =
get_first_ant_idx(das,
p->nb_rx,
p->pdu.beamforming.prgs_list[0].dig_bf_interface_list[0].beam_idx,
p->pdu.param_v4.numSpatialStreamIndices > 0 ? p->pdu.param_v4.spatialStreamIndices[ant_offset] : 0);
for (int aa = 0; aa < p->nb_rx; aa++) {
// Fixme: slot or slot makes no sense ???
int slot2 = p->prach_sequence_length ? p->slot : p->slot;
int idx = ant_start + aa;
c16_t *prach = (c16_t *)&rxdata[idx][get_samples_slot_timestamp(fp, slot2) + sample_offset_slot - N_TA_offset];
// do DFT
c16_t *prach2 = prach + Ncp;
c16_t rxsigF_tmp[N_ZC];
memset(rxsigF_tmp, 0, sizeof(rxsigF_tmp));
for (int i = 0; i < reps; i++, prach2 += dftlen) {
c16_t tmp[dftlen] __attribute__((aligned(32)));
dft(dftsize, (int16_t *)prach2, (int16_t *)tmp, 1);
// Coherent combining of PRACH repetitions (assumes channel does not change, to be revisted for "long" PRACH)
LOG_D(PHY, "Doing PRACH combining of %d reptitions N_ZC %d\n", reps, N_ZC);
// if (k+N_ZC > dftlen) { // PRACH signal is split around DC
int k2 = k;
for (int j = 0; j < N_ZC; j++, k2++) {
if (k2 == dftlen)
k2 = 0;
rxsigF_tmp[j] = c16add(rxsigF_tmp[j], tmp[k2]);
}
}
memcpy(p->prach_buf[aa][prachOccasion], rxsigF_tmp, sizeof(rxsigF_tmp));
for (int rep = 0; rep < params.reps; rep++) {
rx_nr_prach_ru_internal_rep(p, ant_start, rxdata, fp, N_TA_offset, rep, &params, rxsigF_tmp);
}
for (int aa = 0; aa < p->nb_rx; aa++) {
memcpy(p->prach_buf[aa][prachOccasion], rxsigF_tmp[aa], sizeof(c16_t) * params.N_ZC);
}
}
@@ -399,6 +391,20 @@ void rx_nr_prach_ru(prach_item_t *p, int32_t **rxdata, NR_DL_FRAME_PARMS *fp, in
}
}
void rx_nr_prach_ru_rep(prach_item_t *p,
int32_t **rxdata,
NR_DL_FRAME_PARMS *fp,
int N_TA_offset,
int rep,
int prachOccasion,
c16_t (*rxsigF)[NR_PRACH_SEQ_LEN_L])
{
int N_dur = get_nr_prach_duration(p->pdu.prach_format);
int prachStartSymbol = p->pdu.prach_start_symbol + prachOccasion * N_dur;
prach_ru_params_t params = get_prach_ru_params(p, prachStartSymbol, fp);
rx_nr_prach_ru_internal_rep(p, 0, rxdata, fp, N_TA_offset, rep, &params, rxsigF);
}
rx_prach_out_t rx_nr_prach(const prach_item_t *in, int occasion)
{
rx_prach_out_t out = {};

7
openair1/PHY/NR_TRANSPORT/nr_transport_proto.h
View File

@@ -124,6 +124,13 @@ typedef struct rx_prach_out {
rx_prach_out_t rx_nr_prach(const prach_item_t *, int occasion);
void rx_nr_prach_ru(prach_item_t *, int32_t **, NR_DL_FRAME_PARMS *frame_parms, int N_TA_offset, bool das);
void rx_nr_prach_ru_rep(prach_item_t *p,
int32_t **rxdata,
NR_DL_FRAME_PARMS *fp,
int N_TA_offset,
int rep,
int prachOccasion,
c16_t (*rxsigF)[NR_PRACH_SEQ_LEN_L]);
void nr_fill_pucch(PHY_VARS_gNB *gNB,
int frame,