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openairinterface5g/openair1/PHY/NR_ESTIMATION/nr_ul_channel_estimation.c
T
Rakesh Mundlamuri be3ad2beba rewrite srs channel estimation to fix memory alignment in SRS channel estimation 
The memory alignment is required to use c16multaddVectRealComplex
in SRS channel interpolation. With a change in SRS comb_offset, the
existing algorithm was giving segmentation fault.

The existing srs channel estimation required memory alignment at two
stages. 1. When k = 0 (the first srs subcarrier), 2. When subcarrier <
K_TC (wrapped around after ofdm_symbol_size). Thus two memory alignments
are required leading to complications.

The srs channel estimation is now simplified to do it linearly instead of
wrapping around. This simplified the memory alignment required only when
k = 0.
2026-01-09 20:49:46 +05:30

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/*
* 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 1.0 (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 "nr_common.h"
#include <string.h>
#include "nr_ul_estimation.h"
#include "PHY/sse_intrin.h"
#include "PHY/NR_REFSIG/nr_refsig.h"
#include "PHY/NR_REFSIG/dmrs_nr.h"
#include "PHY/NR_REFSIG/ptrs_nr.h"
#include "PHY/NR_TRANSPORT/nr_transport_proto.h"
#include "PHY/NR_UE_ESTIMATION/filt16a_32.h"
#include "PHY/NR_TRANSPORT/nr_sch_dmrs.h"
#include "PHY/NR_REFSIG/ul_ref_seq_nr.h"
#include "executables/softmodem-common.h"
#include "nr_phy_common.h"
#include "openair1/PHY/TOOLS/phy_scope_interface.h"
//#define DEBUG_CH
//#define DEBUG_PUSCH
//#define SRS_DEBUG
#define NO_INTERP 1
#define dBc(x, y) (dB_fixed(((int32_t)(x)) * (x) + ((int32_t)(y)) * (y)))
typedef struct puschAntennaProc_s {
unsigned char Ns;
int nl;
unsigned short p;
unsigned char symbol;
unsigned short bwp_start_subcarrier;
int aarx;
int beam_nb;
int numAntennas;
nfapi_nr_pusch_pdu_t *pusch_pdu;
int *max_ch;
c16_t *pilot;
int *nest_count;
uint64_t *noise_amp2;
delay_t *delay;
int chest_freq;
NR_gNB_PUSCH *pusch_vars;
NR_DL_FRAME_PARMS *frame_parms;
c16_t ***rxdataF;
task_ans_t *ans;
scopeData_t *scope;
c16_t *pusch_ch_est_dmrs_pos_slot_mem;
int dmrs_symbol_start_idx;
} puschAntennaProc_t;
__attribute__((always_inline)) inline c16_t c32x16cumulVectVectWithSteps(c16_t *in1,
int *offset1,
const int step1,
c16_t *in2,
int *offset2,
const int step2,
const int modulo2,
const int N)
{
int localOffset1 = *offset1;
int localOffset2 = *offset2;
c32_t cumul = {0};
for (int i = 0; i < N; i++) {
cumul = c32x16maddShift(in1[localOffset1], in2[localOffset2], cumul, 15);
localOffset1 += step1;
localOffset2 = (localOffset2 + step2) % modulo2;
}
*offset1 = localOffset1;
*offset2 = localOffset2;
return c16x32div(cumul, N);
}
static void nr_pusch_antenna_processing(void *arg)
{
puschAntennaProc_t *rdata = (puschAntennaProc_t *)arg;
unsigned char Ns = rdata->Ns;
int nl = rdata->nl;
unsigned short p = rdata->p;
unsigned char symbol = rdata->symbol;
int aarx = rdata->aarx;
int numAntennas = rdata->numAntennas;
unsigned short bwp_start_subcarrier = rdata->bwp_start_subcarrier;
nfapi_nr_pusch_pdu_t *pusch_pdu = rdata->pusch_pdu;
int *max_ch = rdata->max_ch;
c16_t *pilot = rdata->pilot;
uint64_t noise_amp2 = *(rdata->noise_amp2);
int nest_count = *(rdata->nest_count);
delay_t *delay = rdata->delay;
const int chest_freq = rdata->chest_freq;
NR_gNB_PUSCH *pusch_vars = rdata->pusch_vars;
c16_t **ul_ch_estimates = (c16_t **)pusch_vars->ul_ch_estimates;
NR_DL_FRAME_PARMS *frame_parms = rdata->frame_parms;
const int symbolSize = frame_parms->ofdm_symbol_size;
const int slot_offset = (Ns % RU_RX_SLOT_DEPTH) * frame_parms->symbols_per_slot * symbolSize;
const int delta = get_delta(p, pusch_pdu->dmrs_config_type);
const int symbol_offset = symbolSize * symbol;
const int k0 = bwp_start_subcarrier;
const int nb_rb_pusch = pusch_pdu->rb_size;
const int beam_nb = rdata->beam_nb;
for (int antenna = aarx; antenna < aarx + numAntennas; antenna++) {
c16_t ul_ls_est[symbolSize] __attribute__((aligned(32)));
memset(ul_ls_est, 0, sizeof(c16_t) * symbolSize);
c16_t *rxdataF = (c16_t *)&rdata->rxdataF[beam_nb][antenna][symbol_offset + slot_offset];
c16_t *ul_ch = &ul_ch_estimates[nl * frame_parms->nb_antennas_rx + antenna][symbol_offset];
memset(ul_ch, 0, sizeof(*ul_ch) * symbolSize);
LOG_D(PHY,
"symbol_offset %d, slot_offset %d, OFDM size %d, Ns = %d, k0 = %d, symbol %d\n",
symbol_offset,
slot_offset,
symbolSize,
Ns,
k0,
symbol);
#ifdef DEBUG_PUSCH
LOG_I(PHY, "symbol_offset %d, delta %d\n", symbol_offset, delta);
LOG_I(PHY, "ch est pilot, N_RB_UL %d\n", frame_parms->N_RB_UL);
LOG_I(PHY,
"bwp_start_subcarrier %d, k0 %d, first_carrier %d, nb_rb_pusch %d\n",
bwp_start_subcarrier,
k0,
frame_parms->first_carrier_offset,
nb_rb_pusch);
LOG_I(PHY, "ul_ch addr %p \n", ul_ch);
#endif
if (pusch_pdu->dmrs_config_type == pusch_dmrs_type1 && chest_freq == 0) {
c16_t *pil = pilot;
int re_offset = k0;
LOG_D(PHY, "PUSCH estimation DMRS type 1, Freq-domain interpolation");
int pilot_cnt = 0;
#if T_TRACER
int ch_est_cnt = 0; // To trace channel coefficients
#endif
for (int n = 0; n < 3 * nb_rb_pusch; n++) {
// LS estimation
c32_t ch = {0};
for (int k_line = 0; k_line <= 1; k_line++) {
re_offset = (k0 + (n << 2) + (k_line << 1) + delta) % symbolSize;
ch = c32x16maddShift(*pil, rxdataF[re_offset], ch, 16);
pil++;
}
c16_t ch16 = {.r = (int16_t)ch.r, .i = (int16_t)ch.i};
*max_ch = max(abs(ch.r), abs(ch.i));
for (int k = pilot_cnt << 1; k < (pilot_cnt << 1) + 4; k++) {
ul_ls_est[k] = ch16;
}
//------------------Write channel parameters to Memory for data recording ------------------//
#if T_TRACER
if (T_ACTIVE(T_GNB_PHY_UL_FD_CHAN_EST_DMRS_POS)) {
// Trace channel coefficients
c16_t *pusch_ch_est_dmrs_pos_slot_mem = rdata->pusch_ch_est_dmrs_pos_slot_mem;
int dmrs_symbol_start_idx = rdata->dmrs_symbol_start_idx;
pusch_ch_est_dmrs_pos_slot_mem[dmrs_symbol_start_idx + delta + ch_est_cnt] = ch16; // 0, 2, 4, 6, 8, location of REs
pusch_ch_est_dmrs_pos_slot_mem[dmrs_symbol_start_idx + delta + ch_est_cnt + 2] = ch16; // 0, 2, 4, 6, 8, location of REs
}
ch_est_cnt += 4;
#endif
pilot_cnt += 2;
}
c16_t ch_estimates_time[frame_parms->ofdm_symbol_size] __attribute__((aligned(32)));
nr_est_delay(frame_parms->ofdm_symbol_size, ul_ls_est, ch_estimates_time, delay);
if (rdata->scope && antenna == 0) {
metadata mt = {.slot = -1, .frame = -1};
scopeData_t *tmp = rdata->scope;
tmp->copyData(tmp, gNBulDelay, ch_estimates_time, sizeof(c16_t), 1, frame_parms->ofdm_symbol_size, 0, &mt);
}
int delay_idx = get_delay_idx(delay->est_delay, MAX_DELAY_COMP);
c16_t *ul_delay_table = frame_parms->delay_table[delay_idx];
#ifdef DEBUG_PUSCH
printf("Estimated delay = %i\n", delay->est_delay >> 1);
#endif
pilot_cnt = 0;
for (int n = 0; n < 3 * nb_rb_pusch; n++) {
// Channel interpolation
for (int k_line = 0; k_line <= 1; k_line++) {
// Apply delay
int k = pilot_cnt << 1;
c16_t ch16 = c16mulShift(ul_ls_est[k], ul_delay_table[k], 8);
#ifdef DEBUG_PUSCH
re_offset = (k0 + (n << 2) + (k_line << 1)) % symbolSize;
c16_t *rxF = &rxdataF[re_offset];
printf("pilot %4d: pil -> (%6d,%6d), rxF -> (%4d,%4d), ch -> (%4d,%4d)\n",
pilot_cnt,
pil->r,
pil->i,
rxF->r,
rxF->i,
ch.r,
ch.i);
#endif
if (pilot_cnt == 0) {
c16multaddVectRealComplex(filt16_ul_p0, &ch16, ul_ch, 16);
} else if (pilot_cnt == 1 || pilot_cnt == 2) {
c16multaddVectRealComplex(filt16_ul_p1p2, &ch16, ul_ch, 16);
} else if (pilot_cnt == (6 * nb_rb_pusch - 1)) {
c16multaddVectRealComplex(filt16_ul_last, &ch16, ul_ch, 16);
} else {
c16multaddVectRealComplex(filt16_ul_middle, &ch16, ul_ch, 16);
if (pilot_cnt % 2 == 0) {
ul_ch += 4;
}
}
pilot_cnt++;
}
}
// Revert delay
pilot_cnt = 0;
ul_ch = &ul_ch_estimates[nl * frame_parms->nb_antennas_rx + antenna][symbol_offset];
int inv_delay_idx = get_delay_idx(-delay->est_delay, MAX_DELAY_COMP);
c16_t *ul_inv_delay_table = frame_parms->delay_table[inv_delay_idx];
for (int n = 0; n < 3 * nb_rb_pusch; n++) {
for (int k_line = 0; k_line <= 1; k_line++) {
int k = pilot_cnt << 1;
ul_ch[k] = c16mulShift(ul_ch[k], ul_inv_delay_table[k], 8);
ul_ch[k + 1] = c16mulShift(ul_ch[k + 1], ul_inv_delay_table[k + 1], 8);
noise_amp2 += c16amp2(c16sub(ul_ls_est[k], ul_ch[k]));
noise_amp2 += c16amp2(c16sub(ul_ls_est[k + 1], ul_ch[k + 1]));
#ifdef DEBUG_PUSCH
re_offset = (k0 + (n << 2) + (k_line << 1)) % symbolSize;
printf("ch -> (%4d,%4d), ch_inter -> (%4d,%4d)\n", ul_ls_est[k].r, ul_ls_est[k].i, ul_ch[k].r, ul_ch[k].i);
#endif
pilot_cnt++;
nest_count += 2;
}
}
} else if (pusch_pdu->dmrs_config_type == pusch_dmrs_type2
&& chest_freq == 0) { // pusch_dmrs_type2 |p_r,p_l,d,d,d,d,p_r,p_l,d,d,d,d|
LOG_D(PHY, "PUSCH estimation DMRS type 2, Freq-domain interpolation\n");
c16_t *pil = pilot;
c16_t *rx = &rxdataF[delta];
for (int n = 0; n < nb_rb_pusch * NR_NB_SC_PER_RB; n += 6) {
c16_t ch0 = c16mulShift(*pil, rx[(k0 + n) % symbolSize], 15);
pil++;
c16_t ch1 = c16mulShift(*pil, rx[(k0 + n + 1) % symbolSize], 15);
pil++;
c16_t ch = c16addShift(ch0, ch1, 1);
*max_ch = max(abs(ch.r), abs(ch.i));
multadd_real_four_symbols_vector_complex_scalar(filt8_rep4, ch, &ul_ls_est[n]);
ul_ls_est[n + 4] = ch;
ul_ls_est[n + 5] = ch;
noise_amp2 += c16amp2(c16sub(ch0, ch));
nest_count += 1;
}
// Delay compensation
c16_t ch_estimates_time[frame_parms->ofdm_symbol_size] __attribute__((aligned(32)));
nr_est_delay(frame_parms->ofdm_symbol_size, ul_ls_est, ch_estimates_time, delay);
if (rdata->scope && antenna == 0) {
metadata mt = {.slot = -1, .frame = -1};
scopeData_t *tmp = rdata->scope;
tmp->copyData(tmp, gNBulDelay, ch_estimates_time, sizeof(c16_t), 1, frame_parms->ofdm_symbol_size, 0, &mt);
}
int delay_idx = get_delay_idx(-delay->est_delay, MAX_DELAY_COMP);
c16_t *ul_delay_table = frame_parms->delay_table[delay_idx];
for (int n = 0; n < nb_rb_pusch * NR_NB_SC_PER_RB; n++) {
ul_ch[n] = c16mulShift(ul_ls_est[n], ul_delay_table[n % 6], 8);
}
}
// this is case without frequency-domain linear interpolation, just take average of LS channel estimates of 6 DMRS REs and use a
// common value for the whole PRB
else if (pusch_pdu->dmrs_config_type == pusch_dmrs_type1) {
LOG_D(PHY, "PUSCH estimation DMRS type 1, no Freq-domain interpolation\n");
c16_t *rxF = &rxdataF[delta];
int pil_offset = 0;
int re_offset = k0;
c16_t ch;
// First PRB
ch = c32x16cumulVectVectWithSteps(pilot, &pil_offset, 1, rxF, &re_offset, 2, symbolSize, 6);
#if NO_INTERP
for (c16_t *end = ul_ch + 12; ul_ch < end; ul_ch++)
*ul_ch = ch;
#else
c16multaddVectRealComplex(filt8_avlip0, &ch, ul_ch, 8);
ul_ch += 8;
c16multaddVectRealComplex(filt8_avlip1, &ch, ul_ch, 8);
ul_ch += 8;
c16multaddVectRealComplex(filt8_avlip2, &ch, ul_ch, 8);
ul_ch -= 12;
#endif
for (int pilot_cnt = 6; pilot_cnt < 6 * (nb_rb_pusch - 1); pilot_cnt += 6) {
ch = c32x16cumulVectVectWithSteps(pilot, &pil_offset, 1, rxF, &re_offset, 2, symbolSize, 6);
*max_ch = max(abs(ch.r), abs(ch.i));
#if NO_INTERP
for (c16_t *end = ul_ch + 12; ul_ch < end; ul_ch++)
*ul_ch = ch;
#else
ul_ch[3].r += (ch.r * 1365) >> 15; // 1/12*16384
ul_ch[3].i += (ch.i * 1365) >> 15; // 1/12*16384
ul_ch += 4;
c16multaddVectRealComplex(filt8_avlip3, &ch, ul_ch, 8);
ul_ch += 8;
c16multaddVectRealComplex(filt8_avlip4, &ch, ul_ch, 8);
ul_ch += 8;
c16multaddVectRealComplex(filt8_avlip5, &ch, ul_ch, 8);
ul_ch -= 8;
#endif
}
// Last PRB
ch = c32x16cumulVectVectWithSteps(pilot, &pil_offset, 1, rxF, &re_offset, 2, symbolSize, 6);
#if NO_INTERP
for (c16_t *end = ul_ch + 12; ul_ch < end; ul_ch++)
*ul_ch = ch;
#else
ul_ch[3].r += (ch.r * 1365) >> 15; // 1/12*16384
ul_ch[3].i += (ch.i * 1365) >> 15; // 1/12*16384
ul_ch += 4;
c16multaddVectRealComplex(filt8_avlip3, &ch, ul_ch, 8);
ul_ch += 8;
c16multaddVectRealComplex(filt8_avlip6, &ch, ul_ch, 8);
#endif
} else { // this is case without frequency-domain linear interpolation, just take average of LS channel estimates of 4 DMRS REs
// and use a common value for the whole PRB
LOG_D(PHY, "PUSCH estimation DMRS type 2, no Freq-domain interpolation");
c16_t *pil = pilot;
int re_offset = (k0 + delta) % symbolSize;
c32_t ch0 = {0};
// First PRB
ch0 = c32x16mulShift(*pil, rxdataF[re_offset], 15);
pil++;
re_offset = (re_offset + 1) % symbolSize;
ch0 = c32x16maddShift(*pil, rxdataF[re_offset], ch0, 15);
pil++;
re_offset = (re_offset + 5) % symbolSize;
ch0 = c32x16maddShift(*pil, rxdataF[re_offset], ch0, 15);
re_offset = (re_offset + 1) % symbolSize;
ch0 = c32x16maddShift(*pil, rxdataF[re_offset], ch0, 15);
pil++;
re_offset = (re_offset + 5) % symbolSize;
c16_t ch = c16x32div(ch0, 4);
#if NO_INTERP
for (c16_t *end = ul_ch + 12; ul_ch < end; ul_ch++)
*ul_ch = ch;
#else
c16multaddVectRealComplex(filt8_avlip0, &ch, ul_ch, 8);
ul_ch += 8;
c16multaddVectRealComplex(filt8_avlip1, &ch, ul_ch, 8);
ul_ch += 8;
c16multaddVectRealComplex(filt8_avlip2, &ch, ul_ch, 8);
ul_ch -= 12;
#endif
for (int pilot_cnt = 4; pilot_cnt < 4 * (nb_rb_pusch - 1); pilot_cnt += 4) {
c32_t ch0;
ch0 = c32x16mulShift(*pil, rxdataF[re_offset], 15);
pil++;
re_offset = (re_offset + 1) % symbolSize;
ch0 = c32x16maddShift(*pil, rxdataF[re_offset], ch0, 15);
pil++;
re_offset = (re_offset + 5) % symbolSize;
ch0 = c32x16maddShift(*pil, rxdataF[re_offset], ch0, 15);
pil++;
re_offset = (re_offset + 1) % symbolSize;
ch0 = c32x16maddShift(*pil, rxdataF[re_offset], ch0, 15);
pil++;
re_offset = (re_offset + 5) % symbolSize;
ch = c16x32div(ch0, 4);
*max_ch = max(abs(ch.r), abs(ch.i));
#if NO_INTERP
for (c16_t *end = ul_ch + 12; ul_ch < end; ul_ch++)
*ul_ch = ch;
#else
ul_ch[3] = c16maddShift(ch, (c16_t){1365, 1365}, (c16_t){0, 0}, 15); // 1365 = 1/12*16384 (full range is +/- 32768)
ul_ch += 4;
c16multaddVectRealComplex(filt8_avlip3, &ch, ul_ch, 8);
ul_ch += 8;
c16multaddVectRealComplex(filt8_avlip4, &ch, ul_ch, 8);
ul_ch += 8;
c16multaddVectRealComplex(filt8_avlip5, &ch, ul_ch, 8);
ul_ch -= 8;
#endif
}
// Last PRB
ch0 = c32x16mulShift(*pil, rxdataF[re_offset], 15);
pil++;
re_offset = (re_offset + 1) % symbolSize;
ch0 = c32x16maddShift(*pil, rxdataF[re_offset], ch0, 15);
pil++;
re_offset = (re_offset + 5) % symbolSize;
ch0 = c32x16maddShift(*pil, rxdataF[re_offset], ch0, 15);
pil++;
re_offset = (re_offset + 1) % symbolSize;
ch0 = c32x16maddShift(*pil, rxdataF[re_offset], ch0, 15);
pil++;
re_offset = (re_offset + 5) % symbolSize;
ch = c16x32div(ch0, 4);
#if NO_INTERP
for (c16_t *end = ul_ch + 12; ul_ch < end; ul_ch++)
*ul_ch = ch;
#else
ul_ch[3] = c16maddShift(ch, (c16_t){1365, 1365}, (c16_t){0, 0}, 15); // 1365 = 1/12*16384 (full range is +/- 32768)
ul_ch += 4;
c16multaddVectRealComplex(filt8_avlip3, &ch, ul_ch, 8);
ul_ch += 8;
c16multaddVectRealComplex(filt8_avlip6, &ch, ul_ch, 8);
#endif
}
#ifdef DEBUG_PUSCH
ul_ch = &ul_ch_estimates[nl * gNB->frame_parms.nb_antennas_rx + aarx][symbol_offset];
for (int idxP = 0; idxP < ceil((float)nb_rb_pusch * 12 / 8); idxP++) {
for (int idxI = 0; idxI < 8; idxI++) {
printf("%d\t%d\t", ul_ch[idxP * 8 + idxI].r, ul_ch[idxP * 8 + idxI].i);
}
printf("%d\n", idxP);
}
#endif
// update the values inside the arrays
*(rdata->noise_amp2) = noise_amp2;
*(rdata->nest_count) = nest_count;
}
completed_task_ans(rdata->ans);
}
int nr_pusch_channel_estimation(PHY_VARS_gNB *gNB,
unsigned char Ns,
int nl,
unsigned short p,
unsigned char symbol,
int ul_id,
int beam_nb,
unsigned short bwp_start_subcarrier,
nfapi_nr_pusch_pdu_t *pusch_pdu,
int *max_ch,
uint32_t *nvar,
c16_t *pusch_dmrs_slot_mem,
c16_t *pusch_ch_est_dmrs_pos_slot_mem)
{
c16_t pilot[3280] __attribute__((aligned(32)));
#ifdef DEBUG_CH
FILE *debug_ch_est;
debug_ch_est = fopen("debug_ch_est.txt", "w");
#endif
const int nb_rb_pusch = pusch_pdu->rb_size;
//------------------generate DMRS------------------//
if (pusch_pdu->transform_precoding == transformPrecoder_disabled) {
// Note: pilot returned by the following function is already the complex conjugate of the transmitted DMRS
NR_DL_FRAME_PARMS *fp = &gNB->frame_parms;
const uint32_t *gold = nr_gold_pusch(fp->N_RB_UL,
fp->symbols_per_slot,
gNB->gNB_config.cell_config.phy_cell_id.value,
pusch_pdu->scid,
Ns,
symbol);
float beta_dmrs_pusch = get_beta_dmrs(pusch_pdu->num_dmrs_cdm_grps_no_data, pusch_pdu->dmrs_config_type == pusch_dmrs_type2);
int16_t dmrs_scaling = (1 / beta_dmrs_pusch) * (1 << 14);
nr_pusch_dmrs_rx(gNB,
Ns,
gold,
pilot,
(1000 + p),
0,
nb_rb_pusch,
(pusch_pdu->bwp_start + pusch_pdu->rb_start) * NR_NB_SC_PER_RB,
pusch_pdu->dmrs_config_type,
dmrs_scaling);
} else { // if transform precoding or SC-FDMA is enabled in Uplink
// NR_SC_FDMA supports type1 DMRS so only 6 DMRS REs per RB possible
const int index = get_index_for_dmrs_lowpapr_seq(nb_rb_pusch * (NR_NB_SC_PER_RB / 2));
const uint8_t u = pusch_pdu->dfts_ofdm.low_papr_group_number;
const uint8_t v = pusch_pdu->dfts_ofdm.low_papr_sequence_number;
c16_t *dmrs_seq = gNB_dmrs_lowpaprtype1_sequence[u][v][index];
LOG_D(PHY, "Transform Precoding params. u: %d, v: %d, index for dmrsseq: %d\n", u, v, index);
AssertFatal(index >= 0,
"Num RBs not configured according to 3GPP 38.211 section 6.3.1.4. For PUSCH with transform precoding, num RBs "
"cannot be multiple of any other primenumber other than 2,3,5\n");
AssertFatal(dmrs_seq != NULL, "DMRS low PAPR seq not found, check if DMRS sequences are generated");
nr_pusch_lowpaprtype1_dmrs_rx(gNB, Ns, dmrs_seq, pilot, 1000, 0, nb_rb_pusch, 0, pusch_pdu->dmrs_config_type);
#ifdef DEBUG_PUSCH
printf("NR_UL_CHANNEL_EST: index %d, u %d,v %d\n", index, u, v);
LOG_M("gNb_DMRS_SEQ.m", "gNb_DMRS_SEQ", dmrs_seq, 6 * nb_rb_pusch, 1, 1);
#endif
}
//------------------------------------------------//
#ifdef DEBUG_PUSCH
for (int i = 0; i < (6 * nb_rb_pusch); i++) {
LOG_I(PHY, "In %s: %d + j*(%d)\n", __FUNCTION__, pilot[i].r, pilot[i].i);
}
#endif
//------------------Write DMRS to Memory for Data Recording ------------------//
int dmrs_symbol_start_idx = symbol * pusch_pdu->nrOfLayers * nb_rb_pusch * NR_NB_SC_PER_RB + nl * nb_rb_pusch * NR_NB_SC_PER_RB;
#if T_TRACER
if (T_ACTIVE(T_GNB_PHY_UL_FD_DMRS)) {
// used by T-Tracer to trace DMRS slot grid
int dmrs_delta = 0; // intialize it to zero currently, derive it later from above functions
for (int i = 0; i < (6 * nb_rb_pusch); i++) {
// the generated DMRs is a complex conjugate of mod table, so flip the sign of imag. part
pusch_dmrs_slot_mem[dmrs_symbol_start_idx + dmrs_delta + i * 2].r = pilot[i].r; // 0, 2, 4, 6, 8, location of REs
pusch_dmrs_slot_mem[dmrs_symbol_start_idx + dmrs_delta + i * 2].i = -pilot[i].i; // 0, 2, 4, 6, 8, location of REs
}
}
#endif
int nest_count = 0;
uint64_t noise_amp2 = 0;
delay_t *delay = &gNB->ulsch[ul_id].delay;
memset(delay, 0, sizeof(*delay));
int nb_antennas_rx = gNB->frame_parms.nb_antennas_rx;
delay_t delay_arr[nb_antennas_rx];
uint64_t noise_amp2_arr[nb_antennas_rx];
int max_ch_arr[nb_antennas_rx];
int nest_count_arr[nb_antennas_rx];
for (int i = 0; i < nb_antennas_rx; ++i) {
max_ch_arr[i] = *max_ch;
nest_count_arr[i] = nest_count;
noise_amp2_arr[i] = noise_amp2;
delay_arr[i] = *delay;
}
notifiedFIFO_t respPuschAarx;
initNotifiedFIFO(&respPuschAarx);
start_meas(&gNB->pusch_channel_estimation_antenna_processing_stats);
int numAntennas = gNB->dmrs_num_antennas_per_thread;
int num_jobs = CEILIDIV(gNB->frame_parms.nb_antennas_rx, numAntennas);
puschAntennaProc_t rdatas[num_jobs];
memset(rdatas, 0, sizeof(rdatas));
task_ans_t ans;
init_task_ans(&ans, num_jobs);
for (int job_id = 0; job_id < num_jobs; job_id++) {
puschAntennaProc_t *rdata = &rdatas[job_id];
task_t task = {.func = nr_pusch_antenna_processing, .args = rdata};
// Local init in the current loop
rdata->Ns = Ns;
rdata->nl = nl;
rdata->p = p;
rdata->symbol = symbol;
rdata->aarx = job_id * numAntennas;
rdata->numAntennas = numAntennas;
rdata->bwp_start_subcarrier = bwp_start_subcarrier;
rdata->pusch_pdu = pusch_pdu;
rdata->max_ch = &max_ch_arr[rdata->aarx];
rdata->pilot = pilot;
rdata->nest_count = &nest_count_arr[rdata->aarx];
rdata->noise_amp2 = &noise_amp2_arr[rdata->aarx];
rdata->delay = &delay_arr[rdata->aarx];
rdata->beam_nb = beam_nb;
rdata->frame_parms = &gNB->frame_parms;
rdata->pusch_vars = &gNB->pusch_vars[ul_id];
rdata->chest_freq = gNB->chest_freq;
rdata->rxdataF = gNB->common_vars.rxdataF;
rdata->scope = gNB->scopeData;
rdata->ans = &ans;
rdata->pusch_ch_est_dmrs_pos_slot_mem = pusch_ch_est_dmrs_pos_slot_mem;
rdata->dmrs_symbol_start_idx = dmrs_symbol_start_idx;
// Call the nr_pusch_antenna_processing function
if (job_id == num_jobs - 1) {
// Run the last job inline
nr_pusch_antenna_processing(rdata);
} else {
pushTpool(&gNB->threadPool, task);
}
} // Antenna Loop
join_task_ans(&ans);
stop_meas(&gNB->pusch_channel_estimation_antenna_processing_stats);
for (int aarx = 0; aarx < gNB->frame_parms.nb_antennas_rx; aarx++) {
*max_ch = max(*max_ch, max_ch_arr[aarx]);
noise_amp2 += noise_amp2_arr[aarx];
nest_count += nest_count_arr[aarx];
}
// get the maximum delay
*delay = delay_arr[0];
for (int aarx = 1; aarx < gNB->frame_parms.nb_antennas_rx; aarx++) {
if (delay_arr[aarx].est_delay >= delay->est_delay) {
*delay = delay_arr[aarx];
}
}
#ifdef DEBUG_CH
fclose(debug_ch_est);
#endif
if (nvar && nest_count > 0) {
*nvar = (uint32_t)(noise_amp2 / nest_count);
}
return 0;
}
/*******************************************************************
*
* NAME : nr_pusch_ptrs_processing
*
* PARAMETERS : gNB : gNB data structure
* rel15_ul : UL parameters
* UE_id : UE ID
* nr_tti_rx : slot rx TTI
* dmrs_symbol_flag: DMRS Symbol Flag
* symbol : OFDM Symbol
* nb_re_pusch : PUSCH RE's
* nb_re_pusch : PUSCH RE's
*
* RETURN : nothing
*
* DESCRIPTION :
* If ptrs is enabled process the symbol accordingly
* 1) Estimate phase noise per PTRS symbol
* 2) Interpolate PTRS estimated value in TD after all PTRS symbols
* 3) Compensated DMRS based estimated signal with PTRS estimation for slot
*********************************************************************/
// #define DEBUG_UL_PTRS
void nr_pusch_ptrs_processing(PHY_VARS_gNB *gNB,
NR_DL_FRAME_PARMS *frame_parms,
nfapi_nr_pusch_pdu_t *rel15_ul,
uint8_t ulsch_id,
uint8_t nr_tti_rx,
unsigned char symbol,
uint32_t nb_re_pusch)
{
NR_gNB_PUSCH *pusch_vars = &gNB->pusch_vars[ulsch_id];
int32_t *ptrs_re_symbol = NULL;
int8_t ret = 0;
uint8_t symbInSlot = rel15_ul->start_symbol_index + rel15_ul->nr_of_symbols;
uint8_t *startSymbIndex = &rel15_ul->start_symbol_index;
uint8_t *nbSymb = &rel15_ul->nr_of_symbols;
uint8_t *L_ptrs = &rel15_ul->pusch_ptrs.ptrs_time_density;
uint8_t *K_ptrs = &rel15_ul->pusch_ptrs.ptrs_freq_density;
uint16_t *dmrsSymbPos = &rel15_ul->ul_dmrs_symb_pos;
uint16_t *ptrsSymbPos = &pusch_vars->ptrs_symbols;
uint8_t *ptrsSymbIdx = &pusch_vars->ptrs_symbol_index;
uint16_t *nb_rb = &rel15_ul->rb_size;
uint8_t *ptrsReOffset = &rel15_ul->pusch_ptrs.ptrs_ports_list[0].ptrs_re_offset;
/* loop over antennas */
for (int aarx = 0; aarx < frame_parms->nb_antennas_rx; aarx++) {
c16_t *phase_per_symbol = (c16_t *)pusch_vars->ptrs_phase_per_slot[aarx];
ptrs_re_symbol = &pusch_vars->ptrs_re_per_slot;
*ptrs_re_symbol = 0;
phase_per_symbol[symbol].i = 0;
/* set DMRS estimates to 0 angle with magnitude 1 */
if (is_dmrs_symbol(symbol, *dmrsSymbPos)) {
/* set DMRS real estimation to 32767 */
phase_per_symbol[symbol].r = INT16_MAX; // 32767
#ifdef DEBUG_UL_PTRS
printf("[PHY][PTRS]: DMRS Symbol %d -> %4d + j*%4d\n", symbol, phase_per_symbol[symbol].r, phase_per_symbol[symbol].i);
#endif
} else { // real ptrs value is set to 0
phase_per_symbol[symbol].r = 0;
}
if (symbol == *startSymbIndex) {
*ptrsSymbPos = 0;
set_ptrs_symb_idx(ptrsSymbPos, *nbSymb, *startSymbIndex, 1 << *L_ptrs, *dmrsSymbPos);
}
/* if not PTRS symbol set current ptrs symbol index to zero*/
*ptrsSymbIdx = 0;
/* Check if current symbol contains PTRS */
if (is_ptrs_symbol(symbol, *ptrsSymbPos)) {
*ptrsSymbIdx = symbol;
/*------------------------------------------------------------------------------------------------------- */
/* 1) Estimate common phase error per PTRS symbol */
/*------------------------------------------------------------------------------------------------------- */
const uint32_t *gold = nr_gold_pusch(frame_parms->N_RB_UL,
frame_parms->symbols_per_slot,
gNB->gNB_config.cell_config.phy_cell_id.value,
rel15_ul->scid,
nr_tti_rx,
symbol);
nr_ptrs_cpe_estimation(*K_ptrs,
*ptrsReOffset,
*nb_rb,
rel15_ul->rnti,
nr_tti_rx,
symbol,
frame_parms->ofdm_symbol_size,
(int16_t *)&pusch_vars->rxdataF_comp[aarx][(symbol * nb_re_pusch)],
gold,
(int16_t *)&phase_per_symbol[symbol],
ptrs_re_symbol);
}
/* For last OFDM symbol at each antenna perform interpolation and compensation for the slot*/
if (symbol == (symbInSlot - 1)) {
/*------------------------------------------------------------------------------------------------------- */
/* 2) Interpolate PTRS estimated value in TD */
/*------------------------------------------------------------------------------------------------------- */
/* If L-PTRS is > 0 then we need interpolation */
if (*L_ptrs > 0) {
ret = nr_ptrs_process_slot(*dmrsSymbPos, *ptrsSymbPos, (int16_t *)phase_per_symbol, *startSymbIndex, *nbSymb);
if (ret != 0) {
LOG_W(PHY, "[PTRS] Compensation is skipped due to error in PTRS slot processing !!\n");
}
}
/*------------------------------------------------------------------------------------------------------- */
/* 3) Compensated DMRS based estimated signal with PTRS estimation */
/*--------------------------------------------------------------------------------------------------------*/
for (uint8_t i = *startSymbIndex; i < symbInSlot; i++) {
/* DMRS Symbol has 0 phase so no need to rotate the respective symbol */
/* Skip rotation if the slot processing is wrong */
if ((!is_dmrs_symbol(i, *dmrsSymbPos)) && (ret == 0)) {
#ifdef DEBUG_UL_PTRS
printf("[PHY][UL][PTRS]: Rotate Symbol %2d with %d + j* %d\n", i, phase_per_symbol[i].r, phase_per_symbol[i].i);
#endif
rotate_cpx_vector((c16_t *)&pusch_vars->rxdataF_comp[aarx][i * nb_re_pusch],
&phase_per_symbol[i],
(c16_t *)&pusch_vars->rxdataF_comp[aarx][i * nb_re_pusch],
((*nb_rb) * NR_NB_SC_PER_RB),
15);
} // if not DMRS Symbol
} // symbol loop
} // last symbol check
} // Antenna loop
}
int nr_srs_channel_estimation(int ant,
int p_index,
uint16_t ofdm_symbol_size,
uint16_t first_carrier_offset,
uint8_t N_symb_SRS,
const nfapi_nr_srs_pdu_t *srs_pdu,
const nr_srs_info_t *nr_srs_info,
const c16_t *srs_generated_signal,
c16_t srs_received_signal[ofdm_symbol_size * N_symb_SRS],
c16_t srs_received_noise[ofdm_symbol_size * N_symb_SRS],
c16_t srs_estimated_channel_freq[ofdm_symbol_size * N_symb_SRS],
c16_t srs_estimated_channel_time[NR_SRS_IDFT_OVERSAMP_FACTOR * ofdm_symbol_size],
c16_t srs_estimated_channel_time_shifted[NR_SRS_IDFT_OVERSAMP_FACTOR * ofdm_symbol_size],
uint32_t *signal_power,
uint32_t *noise_power,
int16_t *noise_power_per_rb)
{
#ifdef SRS_DEBUG
LOG_I(NR_PHY, "Calling %s function\n", __FUNCTION__);
#endif
const uint64_t subcarrier_offset = first_carrier_offset + srs_pdu->bwp_start * NR_NB_SC_PER_RB;
const uint64_t first_subcarrier = (first_carrier_offset - (ofdm_symbol_size >> 1)) + srs_pdu->bwp_start * NR_NB_SC_PER_RB;
const uint8_t N_ap = 1 << srs_pdu->num_ant_ports;
const uint8_t K_TC = 2 << srs_pdu->comb_size;
const uint16_t m_SRS_b = get_m_srs(srs_pdu->config_index, srs_pdu->bandwidth_index);
const uint16_t M_sc_b_SRS = m_SRS_b * NR_NB_SC_PER_RB / K_TC;
uint8_t fd_cdm = N_ap;
if (N_ap == 4 && ((K_TC == 2 && srs_pdu->cyclic_shift >= 4) || (K_TC == 4 && srs_pdu->cyclic_shift >= 6))) {
fd_cdm = 2;
}
uint16_t subcarrier;
c16_t srs_ls_estimated_channel[ofdm_symbol_size * N_symb_SRS];
c16_t srs_estimated_channel_freq_avg[ofdm_symbol_size];
memset(srs_ls_estimated_channel, 0, ofdm_symbol_size * N_symb_SRS * sizeof(c16_t));
memset(srs_estimated_channel_freq_avg, 0, ofdm_symbol_size * sizeof(c16_t));
for (int srs_symb = 0; srs_symb < N_symb_SRS; srs_symb++) {
uint16_t srs_symbol_offset = srs_symb * ofdm_symbol_size;
// Additional 4 in the array size is needed to maintain 16 byte memory alignment required for AVX2 instructions in channel
// interpolation
c16_t srs_est[ofdm_symbol_size + 4] __attribute__((aligned(32)));
memset(srs_est, 0, (ofdm_symbol_size + 4) * sizeof(c16_t));
// Estimate 16 byte memory alignment offset for the first SRS subcarrier to use AVX2 instructions in channel interpolation
uint8_t mem_offset = (16 - (((intptr_t)&srs_est[first_subcarrier + nr_srs_info->k_0_p[p_index][srs_symb]]) & 0xF))
>> 2; // >> 2 <=> /sizeof(int32_t)
c16_t ls_estimated = {0};
#ifdef SRS_DEBUG
LOG_I(NR_PHY, "====================== UE port %d --> gNB Rx antenna %i ======================\n", p_index, ant);
LOG_I(NR_PHY, "============================== SRS symbol index %d ===========================\n", srs_symb);
#endif
subcarrier = subcarrier_offset + nr_srs_info->k_0_p[p_index][srs_symb];
if (subcarrier >= ofdm_symbol_size) {
subcarrier -= ofdm_symbol_size;
}
uint16_t subcarrier_abs = mem_offset + first_subcarrier + nr_srs_info->k_0_p[p_index][srs_symb];
c16_t *srs_estimated_channel16 = &srs_est[subcarrier_abs];
for (int k = 0; k < M_sc_b_SRS; k++) {
if (k % fd_cdm == 0) {
ls_estimated = (c16_t){0, 0};
uint16_t subcarrier_cdm = subcarrier;
for (int cdm_idx = 0; cdm_idx < fd_cdm; cdm_idx++) {
c16_t generated_srs = srs_generated_signal[srs_symbol_offset + subcarrier_cdm];
c16_t received_srs = srs_received_signal[srs_symbol_offset + subcarrier_cdm];
// We know that nr_srs_info->srs_generated_signal_bits bits are enough to represent the real and imaginary parts of
// generated_srs. So we only need a nr_srs_info->srs_generated_signal_bits shift to ensure that the result fits into 16
// bits.
ls_estimated = c16maddConjShift(generated_srs, received_srs, ls_estimated, nr_srs_info->srs_generated_signal_bits);
// Subcarrier increment
subcarrier_cdm += K_TC;
if (subcarrier_cdm >= ofdm_symbol_size) {
subcarrier_cdm = subcarrier_cdm - ofdm_symbol_size;
}
}
}
srs_ls_estimated_channel[srs_symbol_offset + subcarrier] = ls_estimated;
#ifdef SRS_DEBUG
int subcarrier_log = subcarrier - subcarrier_offset;
if (subcarrier_log < 0) {
subcarrier_log = subcarrier_log + ofdm_symbol_size;
}
if (subcarrier_log % 12 == 0) {
LOG_I(NR_PHY, "------------------------------------ %d ------------------------------------\n", subcarrier_log / 12);
LOG_I(NR_PHY, "\t __genRe________genIm__|____rxRe_________rxIm__|____lsRe________lsIm_\n");
}
LOG_I(NR_PHY,
"(%4i) %6i\t%6i | %6i\t%6i | %6i\t%6i\n",
subcarrier_log,
srs_generated_signal[srs_symbol_offset + subcarrier].r,
srs_generated_signal[srs_symbol_offset + subcarrier].i,
srs_received_signal[srs_symbol_offset + subcarrier].r,
srs_received_signal[srs_symbol_offset + subcarrier].i,
ls_estimated.r,
ls_estimated.i);
#endif
// Channel interpolation
if (srs_pdu->comb_size == 0) {
if (k == 0) { // First subcarrier case
// filt8_start is {12288,8192,4096,0,0,0,0,0}
c16multaddVectRealComplex(filt8_start, &ls_estimated, srs_estimated_channel16, 8);
} else if (k == (M_sc_b_SRS - 1)) { // End of OFDM symbol or last subcarrier cases
// filt8_end is {4096,8192,12288,16384,0,0,0,0}
c16multaddVectRealComplex(filt8_end, &ls_estimated, srs_estimated_channel16, 8);
} else if (k % 2 == 1) { // 1st middle case
// filt8_middle2 is {4096,8192,8192,8192,4096,0,0,0}
c16multaddVectRealComplex(filt8_middle2, &ls_estimated, srs_estimated_channel16, 8);
} else if (k % 2 == 0) { // 2nd middle case
// filt8_middle4 is {0,0,4096,8192,8192,8192,4096,0}
c16multaddVectRealComplex(filt8_middle4, &ls_estimated, srs_estimated_channel16, 8);
srs_estimated_channel16 = &srs_est[subcarrier_abs];
}
} else {
if (k == 0) { // First subcarrier case
// filt16_start is {12288,8192,8192,8192,4096,0,0,0,0,0,0,0,0,0,0,0}
c16multaddVectRealComplex(filt16_start, &ls_estimated, srs_estimated_channel16, 16);
} else if (k == (M_sc_b_SRS - 1)) { // End of OFDM symbol or last subcarrier cases
// filt16_end is {4096,8192,8192,8192,12288,16384,16384,16384,0,0,0,0,0,0,0,0}
c16multaddVectRealComplex(filt16_end, &ls_estimated, srs_estimated_channel16, 16);
} else { // Middle case
// filt16_middle4 is {4096,8192,8192,8192,8192,8192,8192,8192,4096,0,0,0,0,0,0,0}
c16multaddVectRealComplex(filt16_middle4, &ls_estimated, srs_estimated_channel16, 16);
srs_estimated_channel16 = &srs_est[subcarrier_abs];
}
}
// Subcarrier increment
subcarrier += K_TC;
if (subcarrier >= ofdm_symbol_size) {
subcarrier -= ofdm_symbol_size;
}
subcarrier_abs += K_TC;
} // for (int k = 0; k < M_sc_b_SRS; k++)
memcpy(&srs_estimated_channel_freq[srs_symbol_offset], &srs_est[mem_offset], ofdm_symbol_size * sizeof(c16_t));
// Average srs channel estimates over multiple symbols
int16_t scale_factor = (1 << 15) / N_symb_SRS;
multadd_complex_vector_real_scalar(&srs_estimated_channel_freq[srs_symbol_offset],
scale_factor,
srs_estimated_channel_freq_avg,
ofdm_symbol_size);
#ifdef SRS_DEBUG
subcarrier = subcarrier_offset + nr_srs_info->k_0_p[p_index][srs_symb];
if (subcarrier >= ofdm_symbol_size) {
subcarrier -= ofdm_symbol_size;
}
subcarrier_abs = first_subcarrier + nr_srs_info->k_0_p[p_index][srs_symb];
for (int k = 0; k < K_TC * M_sc_b_SRS; k++) {
int subcarrier_log = subcarrier - subcarrier_offset;
if (subcarrier_log < 0) {
subcarrier_log = subcarrier_log + ofdm_symbol_size;
}
if (subcarrier_log % 12 == 0) {
LOG_I(NR_PHY,
"---------------------------- PRB %d, symbol %d -------------------------------\n",
subcarrier_log / 12,
srs_symb);
LOG_I(NR_PHY, "\t __lsRe__________lsIm__|____intRe_______intIm__|____noiRe_______noiIm__\n");
}
LOG_I(NR_PHY,
"(%4i) %6i\t%6i | %6i\t%6i | %6i\t%6i\n",
subcarrier_log,
srs_ls_estimated_channel[srs_symbol_offset + subcarrier].r,
srs_ls_estimated_channel[srs_symbol_offset + subcarrier].i,
srs_estimated_channel_freq[srs_symbol_offset + subcarrier_abs].r,
srs_estimated_channel_freq[srs_symbol_offset + subcarrier_abs].i,
srs_received_noise[srs_symbol_offset + subcarrier].r,
srs_received_noise[srs_symbol_offset + subcarrier].i);
// Subcarrier increment
subcarrier++;
if (subcarrier >= ofdm_symbol_size) {
subcarrier -= ofdm_symbol_size;
}
subcarrier_abs++;
}
#endif
}
// Convert to time domain
int16_t ofdm_symbol_size_half = ofdm_symbol_size >> 1;
int16_t ofdm_os_size = NR_SRS_IDFT_OVERSAMP_FACTOR * ofdm_symbol_size;
int16_t ofdm_os_size_half = ofdm_os_size >> 1;
int16_t start_offset = ofdm_os_size - ofdm_symbol_size_half;
c16_t chF_interpol[ofdm_os_size] __attribute__((aligned(32)));
memset(chF_interpol, 0, sizeof(chF_interpol));
// Place SRS channel estimates in FFT shifted format for oversampling
memcpy(&chF_interpol[0], &srs_estimated_channel_freq_avg[ofdm_symbol_size_half], ofdm_symbol_size_half * sizeof(c16_t));
memcpy(&chF_interpol[start_offset], &srs_estimated_channel_freq_avg[0], ofdm_symbol_size_half * sizeof(c16_t));
// Convert to time domain oversampled
freq2time(ofdm_os_size, (int16_t *)chF_interpol, (int16_t *)srs_estimated_channel_time);
// Do FFT shift
memcpy(srs_estimated_channel_time_shifted, &srs_estimated_channel_time[ofdm_os_size_half], ofdm_os_size_half * sizeof(c16_t));
memcpy(&srs_estimated_channel_time_shifted[ofdm_os_size_half], srs_estimated_channel_time, ofdm_os_size_half * sizeof(c16_t));
// Compute wideband SNR on the symbol 0
int tot_subcarriers = m_SRS_b * NR_NB_SC_PER_RB;
uint16_t subcarrier_abs = first_subcarrier + nr_srs_info->k_0_p[p_index][0];
if (subcarrier_abs + tot_subcarriers < ofdm_symbol_size_half) {
*signal_power = signal_energy_nodc(&srs_estimated_channel_freq[subcarrier_abs], tot_subcarriers) / tot_subcarriers;
} else {
int size1 = ofdm_symbol_size_half - subcarrier_abs;
int size2 = tot_subcarriers - size1;
uint64_t signal_power_p1 = signal_energy_nodc(&srs_estimated_channel_freq[subcarrier_abs], size1) * size1;
uint64_t signal_power_p2 = signal_energy_nodc(&srs_estimated_channel_freq[ofdm_symbol_size_half], size2) * size2;
*signal_power = (signal_power_p1 + signal_power_p2) / tot_subcarriers;
}
if (*signal_power == 0) {
LOG_W(NR_PHY, "Received SRS signal power is 0\n");
return -1;
}
subcarrier = subcarrier_offset + nr_srs_info->k_0_p[p_index][0];
if (subcarrier >= ofdm_symbol_size) {
subcarrier -= ofdm_symbol_size;
}
if (p_index == 0) {
if (subcarrier + tot_subcarriers < ofdm_symbol_size) {
*noise_power = signal_energy_nodc(&srs_received_noise[subcarrier], tot_subcarriers) / tot_subcarriers;
} else {
int size1 = ofdm_symbol_size - subcarrier;
int size2 = tot_subcarriers - size1;
uint64_t noise_power_p1 = signal_energy_nodc(&srs_received_noise[subcarrier], size1) * size1;
uint64_t noise_power_p2 = signal_energy_nodc(&srs_received_noise[0], size2) * size2;
*noise_power = (noise_power_p1 + noise_power_p2) / tot_subcarriers;
}
}
// Compute SNR per RB for port 0 and symbol 0
if (p_index == 0) {
subcarrier = subcarrier_offset + nr_srs_info->k_0_p[p_index][0];
for (int rb = 0; rb < m_SRS_b; rb++) {
if (subcarrier >= ofdm_symbol_size) {
subcarrier -= ofdm_symbol_size;
}
if (subcarrier + NR_NB_SC_PER_RB < ofdm_symbol_size) {
noise_power_per_rb[rb] += signal_energy_nodc(&srs_received_noise[subcarrier], NR_NB_SC_PER_RB);
} else {
int size1 = ofdm_symbol_size - subcarrier;
int size2 = NR_NB_SC_PER_RB - size1;
uint32_t noise_power_per_rb1 = signal_energy_nodc(&srs_received_noise[subcarrier], size1) * size1;
uint32_t noise_power_per_rb2 = signal_energy_nodc(&srs_received_noise[0], size2) * size2;
noise_power_per_rb[rb] += (noise_power_per_rb1 + noise_power_per_rb2) / NR_NB_SC_PER_RB;
}
noise_power_per_rb[rb] = max(noise_power_per_rb[rb], 1);
subcarrier += NR_NB_SC_PER_RB;
#ifdef SRS_DEBUG
LOG_I(NR_PHY,
"[RB %3i] noise_power_per_rb = %i, SNR_per_rb = %i dB\n",
rb,
noise_power_per_rb[rb],
dB_fixed(*signal_power) - dB_fixed(noise_power_per_rb[rb]));
#endif
}
}
#ifdef SRS_DEBUG
int32_t signal_power_dB = dB_fixed(*signal_power);
int32_t noise_power_dB = dB_fixed(*noise_power);
LOG_I(NR_PHY,
"signal_power = %i dB, noise_power = %i dB, SNR = %i dB\n",
signal_power_dB,
noise_power_dB,
signal_power_dB - noise_power_dB);
#endif
return 0;
}
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