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Split the code in the SNR loop as functions for readability

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- Introduce signal energy and noise variance functions
- Combine rotation and OFDM modulation RX as a function
- Harmonize the use of number of antennas across the code
- Rename nr_ue_pusch_common_procedures() to nr_tx_rotation_and_ofdm_mod() to decribe the functionality better
This commit is contained in:
Rakesh Mundlamuri
2026-01-09 16:58:34 +05:30
parent 14cfbbf425
commit 729dc02b88
11 changed files with 139 additions and 128 deletions
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openair1/SIMULATION/NR_PHY/srssim.c
+28 -71
View File
@@ -88,7 +88,6 @@ int main(int argc, char *argv[])
sigaction(SIGINT, &sigint_action, &oldaction);
double SNR, snr0 = 0, snr1 = 20.0;
double sigma, sigma_dB;
double snr_step = 1;
uint8_t snr1set = 0;
double **s_re, **s_im, **r_re, **r_im;
@@ -105,7 +104,6 @@ int main(int argc, char *argv[])
int srs_comb_offset = 0;
int srs_cyclic_shift = 0;
int nb_symb_srs = 0;
int32_t txlev_sum = 0, atxlev[4];
int i;
int loglvl = OAILOG_WARNING;
int print_perf = 0;
@@ -502,44 +500,31 @@ int main(int argc, char *argv[])
uint16_t ofdm_symbol_size = fp->ofdm_symbol_size;
int slot_offsetF = (slot % RU_RX_SLOT_DEPTH) * NR_SYMBOLS_PER_SLOT * ofdm_symbol_size;
c16_t *txF[fp->nb_antennas_tx];
for (i = 0; i < fp->nb_antennas_tx; i++)
c16_t *txF[n_tx];
for (i = 0; i < n_tx; i++)
txF[i] = txdataF[i] + slot_offsetF;
c16_t *txd[n_tx];
for (i = 0; i < n_tx; i++)
txd[i] = txdata[i] + slot_offset;
ue_srs_procedures_nr(UE, &proc, (c16_t **)txF, &phy_data, was_symbol_used);
//------------ TX rotation and OFDM Modulation --------------------------
for (int aa = 0; aa < fp->nb_antennas_tx; aa++) {
apply_nr_rotation_TX(fp, &txF[aa][0], fp->symbol_rotation[1], slot, fp->N_RB_UL, 0, fp->Ncp == EXTENDED ? 12 : 14);
if (srs_pdu.cyclic_prefix == 1) {
for (i = 0; i < NR_NUMBER_OF_SYMBOLS_PER_SLOT_EXTENDED_CP; i++) {
if (was_symbol_used[i] == true) {
PHY_ofdm_mod((int *)&txF[aa][0],
(int *)&txdata[aa][slot_offset + (ofdm_symbol_size + fp->nb_prefix_samples) * i],
ofdm_symbol_size,
1,
fp->nb_prefix_samples,
CYCLIC_PREFIX);
}
}
} else {
nr_normal_prefix_mod(&txF[aa][0], &txdata[aa][slot_offset], fp->symbols_per_slot, fp, slot, was_symbol_used);
}
}
nr_tx_rotation_and_ofdm_mod(slot, fp, n_tx, txF, txd, link_type_ul, was_symbol_used, false);
//----------- Apply propagation channel and add noise ----------------------------
double ts = 1.0 / (fp->subcarrier_spacing * ofdm_symbol_size);
for (i = 0; i < slot_length; i++) {
for (int aa = 0; aa < UE->frame_parms.nb_antennas_tx; aa++) {
for (int aa = 0; aa < n_tx; aa++) {
s_re[aa][i] = (double)txdata[aa][slot_offset + i].r;
s_im[aa][i] = (double)txdata[aa][slot_offset + i].i;
}
}
// Compute SRS symbol offset
// Compute SRS symbol offset and length
int symbol_offset = slot_offset;
int abs_first_symbol = slot * fp->symbols_per_slot;
int idx_sym;
@@ -547,19 +532,10 @@ int main(int argc, char *argv[])
symbol_offset += (idx_sym % (0x7 << fp->numerology_index)) ? fp->nb_prefix_samples : fp->nb_prefix_samples0;
symbol_offset += ofdm_symbol_size * srs_pdu.time_start_position;
int symbol_length = ofdm_symbol_size + (idx_sym % (0x7 << fp->numerology_index)) ? fp->nb_prefix_samples : fp->nb_prefix_samples0;
// Compute transmitter level
txlev_sum = 0;
for (int aa = 0; aa < UE->frame_parms.nb_antennas_tx; aa++) {
atxlev[aa] = signal_energy(
(int32_t *)&txdata[aa][symbol_offset],
ofdm_symbol_size + (idx_sym % (0x7 << fp->numerology_index)) ? fp->nb_prefix_samples : fp->nb_prefix_samples0);
txlev_sum += atxlev[aa];
if (n_trials == 1)
printf("txlev[%d] = %d (%f dB) txlev_sum %d\n", aa, atxlev[aa], 10 * log10((double)atxlev[aa]), txlev_sum);
}
// Compute transmitter energy level
double txlev_sum = compute_tx_energy_level(txdata, n_tx, symbol_offset, symbol_length, n_trials);
for (SNR = snr0; SNR <= snr1 && !stop; SNR += snr_step) {
varArray_t *table_rx = initVarArray(1000, sizeof(double));
@@ -573,15 +549,7 @@ int main(int argc, char *argv[])
int tao_ns_count = 0;
for (trial = 0; trial < n_trials && !stop; trial++) {
// Estimate noise power from the transmitter level and SNR
sigma_dB = 10 * log10(((double)txlev_sum) * ((double)ofdm_symbol_size / (12 * srs_pdu.bwp_size))) - SNR;
sigma = pow(10, sigma_dB / 10);
if (n_trials == 1)
printf("sigma %f (%f dB), txlev_sum %f (factor %f)\n",
sigma,
sigma_dB,
10 * log10((double)txlev_sum),
(double)(double)ofdm_symbol_size / (12 * srs_pdu.bwp_size));
double sigma = compute_noise_variance(txlev_sum, ofdm_symbol_size, srs_pdu.bwp_size, SNR, n_trials);
//----------- Apply propagation channel ----------------------------
multipath_channel(UE2gNB, s_re, s_im, r_re, r_im, slot_length, 0, (n_trials == 1) ? 1 : 0);
@@ -590,34 +558,24 @@ int main(int argc, char *argv[])
add_noise(rxdata,
(const double **)r_re,
(const double **)r_im,
sigma,
sigma, // noise power
slot_length,
slot_offset,
ts,
0, // delay
0, // pdu_bit_map
0, // PTRS_BITMAP,
fp->nb_antennas_rx);
n_rx);
//----------- OFDM Demodulation and RX rotation--------------------------
for (uint8_t symbol = 0; symbol < (fp->Ncp == EXTENDED ? 12 : 14); symbol++) {
for (int aa = 0; aa < fp->nb_antennas_rx; aa++)
nr_slot_fep_ul(fp, (int32_t *)&rxdata[aa][0], (int32_t *)&gNB->common_vars.rxdataF[0][aa][slot_offsetF], symbol, slot, 0);
}
for (int aa = 0; aa < fp->nb_antennas_rx; aa++) {
for (uint8_t symbol = 0; symbol < fp->symbols_per_slot; symbol++) {
if (was_symbol_used[symbol] == true) {
apply_nr_rotation_symbol_RX(fp,
&gNB->common_vars.rxdataF[0][aa][slot_offsetF + symbol * fp->ofdm_symbol_size],
fp->symbol_rotation[1],
fp->N_RB_UL,
slot,
symbol);
}
}
}
nr_ofdm_demod_and_rx_rotation(rxdata,
gNB->common_vars.rxdataF[0],
fp,
n_rx,
slot,
slot_offsetF,
link_type_ul,
was_symbol_used);
//----------- UE RX SRS procedures ---------------------
@@ -625,18 +583,17 @@ int main(int argc, char *argv[])
NR_gNB_SRS_t *srs = &gNB->srs[0];
uint8_t N_symb_SRS = 1 << srs->srs_pdu.num_symbols;
uint8_t N_ap = 1 << srs->srs_pdu.num_ant_ports;
uint8_t nb_antennas_rx = fp->nb_antennas_rx;
int16_t snr_per_rb[srs->srs_pdu.bwp_size];
uint16_t timing_advance_offset;
int16_t timing_advance_offset_nsec[nb_antennas_rx];
int16_t timing_advance_offset_nsec[n_rx];
int srs_est;
c16_t srs_estimated_channel_freq[nb_antennas_rx][N_ap][ofdm_symbol_size * N_symb_SRS] __attribute__((aligned(32)));
c16_t srs_estimated_channel_time[nb_antennas_rx][N_ap][ofdm_symbol_size] __attribute__((aligned(32)));
c16_t srs_estimated_channel_freq[n_rx][N_ap][ofdm_symbol_size * N_symb_SRS] __attribute__((aligned(32)));
c16_t srs_estimated_channel_time[n_rx][N_ap][ofdm_symbol_size] __attribute__((aligned(32)));
nr_srs_rx_procedures(gNB,
frame,
slot,
nb_antennas_rx,
n_rx,
N_ap,
N_symb_SRS,
ofdm_symbol_size,
@@ -652,7 +609,7 @@ int main(int argc, char *argv[])
sum_srs_snr += pow(10, (double)gNB->srs->snr / 10.0);
int16_t delay_ns = delay * 1e9 / (fp->samples_per_frame * 100);
for (int ant_idx = 0; ant_idx < nb_antennas_rx; ant_idx++) {
for (int ant_idx = 0; ant_idx < n_rx; ant_idx++) {
if (n_trials == 1)
printf("[RX ant %d] SRS estimated: TA offset %d, TA offset ns %d \n",
ant_idx,
openair1/SIMULATION/NR_PHY/ulsim.c
+12 -18
View File
@@ -1460,26 +1460,20 @@ int main(int argc, char *argv[])
UL_INFO.crc_ind.number_crcs = 0;
UL_INFO.srs_ind.number_of_pdus = 0;
for(uint8_t symbol = 0; symbol < (gNB->frame_parms.Ncp == EXTENDED ? 12 : 14); symbol++) {
for (int aa = 0; aa < gNB->frame_parms.nb_antennas_rx; aa++)
nr_slot_fep_ul(&gNB->frame_parms,
(int32_t *)rxdata[aa],
(int32_t *)gNB->common_vars.rxdataF[0][aa],
symbol,
slot,
0);
}
//----------- OFDM Demodulation and RX rotation--------------------------
bool was_symbol_used[14] = {0};
int offset = (slot & 3) * gNB->frame_parms.symbols_per_slot * gNB->frame_parms.ofdm_symbol_size;
for (int aa = 0; aa < gNB->frame_parms.nb_antennas_rx; aa++) {
const unsigned int max_symb = (gNB->frame_parms.Ncp == EXTENDED) ? 12 : 14;
for (int sym = 0; sym < max_symb; sym++)
apply_nr_rotation_symbol_RX(&gNB->frame_parms,
gNB->common_vars.rxdataF[0][aa] + offset + sym * gNB->frame_parms.ofdm_symbol_size,
gNB->frame_parms.symbol_rotation[1],
gNB->frame_parms.N_RB_UL,
slot,
sym);
for (int i = 0; i < 14; i++) {
was_symbol_used[i] = true;
}
nr_ofdm_demod_and_rx_rotation(rxdata,
gNB->common_vars.rxdataF[0],
&gNB->frame_parms,
gNB->frame_parms.nb_antennas_rx,
slot,
offset,
link_type_ul,
was_symbol_used);
ul_proc_error = phy_procedures_gNB_uespec_RX(gNB, frame, slot, &UL_INFO);