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Fixes and improvements in generate_srs_nr function

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This commit is contained in:
Roberto Louro Magueta
2022-05-14 21:01:42 +01:00
parent f6bc787d1e
commit 52bc76d904
3 changed files with 290 additions and 266 deletions
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openair1/PHY/NR_ESTIMATION/nr_ul_channel_estimation.c
+1 -1
View File
@@ -1144,7 +1144,7 @@ int nr_srs_channel_estimation(PHY_VARS_gNB *gNB,
*snr = dB_fixed((int32_t)((*signal_power<<factor_bits)/(*noise_power))) - factor_dB;
#ifdef SRS_DEBUG
uint64_t subcarrier_offset = frame_parms->first_carrier_offset + srs_pdu->bwp_start*12;
subcarrier_offset = frame_parms->first_carrier_offset + srs_pdu->bwp_start*12;
uint8_t R = srs_pdu->comb_size == 0 ? 2 : 4;
for (int ant = 0; ant < frame_parms->nb_antennas_rx; ant++) {
for(int sc_idx = 0; sc_idx < nr_srs_info->sc_list_length; sc_idx++) {
openair1/PHY/NR_UE_TRANSPORT/srs_modulation_nr.c
+282 -265
View File
@@ -48,9 +48,129 @@
//#define SRS_DEBUG
/*******************************************************************
uint16_t group_number_hopping(int slot_number,
uint8_t n_ID_SRS,
uint8_t l0,
uint8_t l_line) {
// Pseudo-random sequence c(i) defined by TS 38.211 - Section 5.2.1
uint32_t cinit = n_ID_SRS;
uint8_t c_last_index = 8 * (slot_number * N_SYMB_SLOT + l0 + l_line) + 7;
uint32_t *c_sequence = calloc(c_last_index+1, sizeof(uint32_t));
pseudo_random_sequence(c_last_index+1, c_sequence, cinit);
// TS 38.211 - 6.4.1.4.2 Sequence generation
uint32_t f_gh = 0;
for (int m = 0; m <= 7; m++) {
f_gh += c_sequence[8 * (slot_number * N_SYMB_SLOT + l0 + l_line) + m] << m;
}
f_gh = f_gh%30;
uint8_t u = (f_gh + n_ID_SRS)%U_GROUP_NUMBER;
free(c_sequence);
return u;
}
uint16_t sequence_number_hopping(int slot_number,
uint8_t n_ID_SRS,
uint16_t M_sc_b_SRS,
uint8_t l0,
uint8_t l_line) {
uint16_t v = 0;
if (M_sc_b_SRS > 6 * N_SC_RB) {
// Pseudo-random sequence c(i) defined by TS 38.211 - Section 5.2.1
uint32_t cinit = n_ID_SRS;
uint8_t c_last_index = (slot_number * N_SYMB_SLOT + l0 + l_line);
uint32_t *c_sequence = calloc(c_last_index+1, sizeof(uint32_t));
pseudo_random_sequence(c_last_index+1, c_sequence, cinit);
// TS 38.211 - 6.4.1.4.2 Sequence generation
v = c_sequence[c_last_index];
free(c_sequence);
}
return v;
}
uint16_t compute_F_b(int frame_number,
int slot_number,
uint16_t slots_per_frame,
uint8_t N_symb_SRS,
uint8_t B_SRS,
uint8_t C_SRS,
uint8_t b_hop,
uint8_t R,
uint16_t T_offset,
uint16_t T_SRS,
uint8_t resource_type,
uint8_t l_line,
uint8_t b) {
// Compute the number of SRS transmissions
uint16_t n_SRS = 0;
if (resource_type == aperiodic) {
n_SRS = l_line / R;
} else {
n_SRS = ((slots_per_frame*frame_number + slot_number - T_offset)/T_SRS)*(N_symb_SRS/R)+(l_line / R);
}
uint16_t product_N_b = 1;
for (unsigned int b_prime = b_hop; b_prime < B_SRS; b_prime++) {
if (b_prime != b_hop) {
product_N_b *= srs_bandwidth_config[C_SRS][b_prime][1];
}
}
uint16_t F_b = 0;
uint8_t N_b = srs_bandwidth_config[C_SRS][b][1];
if (N_b & 1) { // Nb odd
F_b = (N_b/2)*(n_SRS/product_N_b);
} else { // Nb even
uint16_t product_N_b_B_SRS = product_N_b;
product_N_b_B_SRS *= srs_bandwidth_config[C_SRS][B_SRS][1]; /* product for b_hop to b */
F_b = (N_b/2)*((n_SRS%product_N_b_B_SRS)/product_N_b) + ((n_SRS%product_N_b_B_SRS)/2*product_N_b);
}
return F_b;
}
uint16_t compute_n_b(int frame_number,
int slot_number,
uint16_t slots_per_frame,
uint8_t N_symb_SRS,
uint8_t B_SRS,
uint8_t C_SRS,
uint8_t b_hop,
uint8_t n_RRC,
uint8_t R,
uint16_t T_offset,
uint16_t T_SRS,
uint8_t resource_type,
uint8_t l_line,
uint8_t b) {
uint8_t N_b = srs_bandwidth_config[C_SRS][b][1];
uint16_t m_SRS_b = srs_bandwidth_config[C_SRS][B_SRS][0];
uint16_t n_b = 0;
if (b_hop >= B_SRS) {
n_b = (4 * n_RRC/m_SRS_b)%N_b;
} else {
if (b <= b_hop) {
n_b = (4 * n_RRC/m_SRS_b)%N_b;
} else {
// Compute the hopping offset Fb
uint16_t F_b = compute_F_b(frame_number, slot_number, slots_per_frame, N_symb_SRS, B_SRS, C_SRS, b_hop, R,
T_offset, T_SRS, resource_type, l_line, b);
n_b = (F_b + (4 * n_RRC/m_SRS_b))%N_b;
}
}
return n_b;
}
/*************************************************************************
*
* NAME : generate_srs
* NAME : generate_srs_nr
*
* PARAMETERS : pointer to srs config pdu
* pointer to transmit buffer
@@ -60,20 +180,9 @@
* -1 if sequence can not be properly generated
*
* DESCRIPTION : generate/map srs symbol into transmit buffer
* see TS 38211 6.4.1.4 Sounding reference signal
* See TS 38.211 - Section 6.4.1.4 Sounding reference signal
*
* FFS_TODO_NR
* Current supported configuration:
* - single resource per resource set
* - single port antenna
* - 1 symbol for SRS
* - no symbol offset
* - periodic mode
* - no hopping
* - no carrier switching
* - no antenna switching*
*
*********************************************************************/
***************************************************************************/
int generate_srs_nr(nfapi_nr_srs_pdu_t *srs_config_pdu,
NR_DL_FRAME_PARMS *frame_parms,
int32_t **txdataF,
@@ -83,46 +192,27 @@ int generate_srs_nr(nfapi_nr_srs_pdu_t *srs_config_pdu,
int frame_number,
int slot_number) {
uint8_t n_SRS_cs_max;
uint8_t u;
uint8_t v_nu;
uint32_t f_gh = 0;
uint16_t n_SRS;
uint16_t n_SRS_cs_i;
double alpha_i;
uint8_t K_TC_p;
uint16_t n_b[B_SRS_NUMBER];
uint16_t F_b;
uint16_t subcarrier;
uint8_t N_b;
uint8_t k_0_overbar_p;
// get parameters from srs_config_pdu
uint8_t B_SRS = srs_config_pdu->bandwidth_index;
uint8_t C_SRS = srs_config_pdu->config_index;
// SRS config parameters
uint8_t B_SRS = srs_config_pdu->bandwidth_index;
uint8_t C_SRS = srs_config_pdu->config_index;
uint8_t b_hop = srs_config_pdu->frequency_hopping;
uint8_t K_TC = 2<<srs_config_pdu->comb_size;
uint8_t K_TC_overbar = srs_config_pdu->comb_offset; // FFS_TODO_NR is this parameter for K_TC_overbar ??
uint8_t K_TC_overbar = srs_config_pdu->comb_offset;
uint8_t n_SRS_cs = srs_config_pdu->cyclic_shift;
uint8_t n_ID_SRS = srs_config_pdu->sequence_id;
uint8_t n_shift = srs_config_pdu->frequency_position; // it adjusts the SRS allocation to align with the common resource block grid in multiples of four
uint8_t n_shift = srs_config_pdu->frequency_position; // It adjusts the SRS allocation to align with the common resource block grid in multiples of four
uint8_t n_RRC = srs_config_pdu->frequency_shift;
uint8_t groupOrSequenceHopping = srs_config_pdu->group_or_sequence_hopping;
uint8_t l_offset = srs_config_pdu->time_start_position;
uint16_t T_SRS = srs_config_pdu->t_srs;
uint16_t T_offset = srs_config_pdu->t_offset; // FFS_TODO_NR to check interface with RRC
uint16_t T_offset = srs_config_pdu->t_offset;
uint8_t R = 1<<srs_config_pdu->num_repetitions;
uint8_t N_ap = 1<<srs_config_pdu->num_ant_ports; // antenna port for transmission
uint8_t N_symb_SRS = 1<<srs_config_pdu->num_symbols; // consecutive OFDM symbols
uint8_t l0 = frame_parms->symbols_per_slot - 1 - l_offset; // starting position in the time domain
uint8_t k_0_p; // frequency domain starting position
uint64_t subcarrier_offset = frame_parms->first_carrier_offset + srs_config_pdu->bwp_start*N_SC_RB;
if(nr_srs_info) {
nr_srs_info->sc_list_length = 0;
nr_srs_info->srs_generated_signal_bits = log2_approx(amp);
}
uint8_t N_ap = 1<<srs_config_pdu->num_ant_ports; // Number of antenna port for transmission
uint8_t N_symb_SRS = 1<<srs_config_pdu->num_symbols; // Number of consecutive OFDM symbols
uint8_t l0 = frame_parms->symbols_per_slot - 1 - l_offset; // Starting symbol position in the time domain
uint8_t n_SRS_cs_max = srs_max_number_cs[srs_config_pdu->comb_size];
uint16_t m_SRS_b = srs_bandwidth_config[C_SRS][B_SRS][0]; // Number of resource blocks
uint16_t M_sc_b_SRS = m_SRS_b * N_SC_RB/K_TC; // Length of the SRS sequence
#ifdef SRS_DEBUG
LOG_I(NR_PHY,"Frame = %i, slot = %i\n", frame_number, slot_number);
@@ -143,263 +233,190 @@ int generate_srs_nr(nfapi_nr_srs_pdu_t *srs_config_pdu,
LOG_I(NR_PHY,"N_ap = %i\n", N_ap);
LOG_I(NR_PHY,"N_symb_SRS = %i\n", N_symb_SRS);
LOG_I(NR_PHY,"l0 = %i\n", l0);
LOG_I(NR_PHY,"n_SRS_cs_max = %i\n", n_SRS_cs_max);
LOG_I(NR_PHY,"m_SRS_b = %i\n", m_SRS_b);
LOG_I(NR_PHY,"M_sc_b_SRS = %i\n", M_sc_b_SRS);
#endif
if (N_symb_SRS != 1) {
LOG_E(NR_PHY, "generate_srs: this number of srs symbol %d is not yet supported!\n", N_symb_SRS);
return (-1);
}
if (groupOrSequenceHopping != neitherHopping) {
LOG_E(NR_PHY, "generate_srs: sequence hopping is not yet supported!\n");
return (-1);
}
// Validation of SRS config parameters
if (R == 0) {
LOG_E(NR_PHY, "generate_srs: this parameter repetition factor %d is not consistent !\n", R);
return (-1);
}
else if (R > N_symb_SRS) {
return -1;
} else if (R > N_symb_SRS) {
LOG_E(NR_PHY, "generate_srs: R %d can not be greater than N_symb_SRS %d !\n", R, N_symb_SRS);
return (-1);
}
/* see 38211 6.4.1.4.2 Sequence generation */
if (K_TC == 4) {
n_SRS_cs_max = 12;
// delta = 2; /* delta = log2(K_TC) */
}
else if (K_TC == 2) {
n_SRS_cs_max = 8;
// delta = 1; /* delta = log2(K_TC) */
}
else {
LOG_E(NR_PHY, "generate_srs: SRS unknown value for K_TC %d !\n", K_TC);
return (-1);
return -1;
}
if (n_SRS_cs >= n_SRS_cs_max) {
LOG_E(NR_PHY, "generate_srs: inconsistent parameter n_SRS_cs %d >= n_SRS_cs_max %d !\n", n_SRS_cs, n_SRS_cs_max);
return (-1);
return -1;
}
if (T_SRS == 0) {
LOG_E(NR_PHY, "generate_srs: inconsistent parameter T_SRS %d can not be equal to zero !\n", T_SRS);
return (-1);
}
else
{
return -1;
} else {
int index = 0;
while (srs_periodicity[index] != T_SRS) {
index++;
if (index == SRS_PERIODICITY) {
LOG_E(NR_PHY, "generate_srs: inconsistent parameter T_SRS %d not specified !\n", T_SRS);
return (-1);
return -1;
}
}
}
uint16_t m_SRS_b = srs_bandwidth_config[C_SRS][B_SRS][0]; /* m_SRS_b is given by TS 38211 clause 6.4.1.4.3 */
uint16_t M_sc_b_SRS = m_SRS_b * N_SC_RB/K_TC; /* length of the sounding reference signal sequence */
// Variable initialization
if(nr_srs_info) {
nr_srs_info->sc_list_length = 0;
nr_srs_info->srs_generated_signal_bits = log2_approx(amp);
}
uint64_t subcarrier_offset = frame_parms->first_carrier_offset + srs_config_pdu->bwp_start*N_SC_RB;
double sqrt_N_ap = sqrt(N_ap);
uint16_t n_b[B_SRS_NUMBER];
/* for each antenna ports for transmission */
// Find index of table which is for this SRS length
uint16_t M_sc_b_SRS_index = 0;
while((ul_allocated_re[M_sc_b_SRS_index] != M_sc_b_SRS) && (M_sc_b_SRS_index < SRS_SB_CONF)){
M_sc_b_SRS_index++;
}
// SRS sequence generation and mapping, TS 38.211 - Section 6.4.1.4
for (int p_index = 0; p_index < N_ap; p_index++) {
int32_t *txptr = &txdataF[p_index][symbol_offset];
/* see TS 38.211 6.4.1.4.2 Sequence generation */
n_SRS_cs_i = (n_SRS_cs + (n_SRS_cs_max * (SRS_antenna_port[p_index] - 1000)/N_ap))%n_SRS_cs_max;
alpha_i = 2 * M_PI * ((double)n_SRS_cs_i / (double)n_SRS_cs_max);
/* for each SRS symbol which should be managed by SRS configuration */
/* from TS 38.214 6.2.1.1 UE SRS frequency hopping procedure */
/* A UE may be configured to transmit an SRS resource on adjacent symbols within the last six symbols of a slot, */
/* where all antenna ports of the SRS resource are mapped to each symbol of the resource */
uint8_t l = p_index;
if (l >= N_symb_SRS) {
LOG_E(NR_PHY, "generate_srs: number of antenna ports %d and number of srs symbols %d are different !\n", N_ap, N_symb_SRS);
}
switch(groupOrSequenceHopping) {
case neitherHopping:
{
f_gh = 0;
v_nu = 0;
break;
}
case groupHopping:
{
uint8_t c_last_index = 8 * (slot_number * N_SYMB_SLOT + l0 + l) + 7; /* compute maximum value of the random sequence */
uint32_t *c_sequence = calloc(c_last_index+1, sizeof(uint32_t));
uint32_t cinit = n_ID_SRS/30;
pseudo_random_sequence(c_last_index+1, c_sequence, cinit);
for (int m = 0; m < 8; m++) {
f_gh += c_sequence[8 * (slot_number * N_SYMB_SLOT + l0 + l) + m]<<m;
}
free(c_sequence);
f_gh = f_gh%30;
v_nu = 0;
break;
}
case sequenceHopping:
{
f_gh = 0;
if (M_sc_b_SRS > 6 * N_SC_RB) {
uint8_t c_last_index = (slot_number * N_SYMB_SLOT + l0 + l); /* compute maximum value of the random sequence */
uint32_t *c_sequence = calloc(c_last_index+1, sizeof(uint32_t));
uint32_t cinit = n_ID_SRS;
pseudo_random_sequence(c_last_index+1, c_sequence, cinit);
v_nu = c_sequence[c_last_index];
free(c_sequence);
}
else {
v_nu = 0;
}
break;
}
default:
{
LOG_E(NR_PHY, "generate_srs: unknown hopping setting %d !\n", groupOrSequenceHopping);
return (-1);
}
}
/* u is the sequence-group number defined in section 6.4.1.4.1 */
u = (f_gh + n_ID_SRS)%U_GROUP_NUMBER; /* 30 */
/* TS 38.211 6.4.1.4.3 Mapping to physical resources */
if((n_SRS_cs >= n_SRS_cs_max/2)&&(n_SRS_cs < n_SRS_cs_max)&&(N_ap == 4) && ((SRS_antenna_port[p_index] == 1001) || (SRS_antenna_port[p_index] == 1003))) {
K_TC_p = (K_TC_overbar + K_TC/2)%K_TC;
}
else {
K_TC_p = K_TC_overbar;
}
for (int b = 0; b <= B_SRS; b++) {
N_b = srs_bandwidth_config[C_SRS][b][1];
if (b_hop >= B_SRS) {
n_b[b] = (4 * n_RRC/m_SRS_b)%N_b; /* frequency hopping is disabled and the frequency position index n_b remains constant */
}
else {
if (b == b_hop) {
N_b = 1;
}
/* periodicity and offset */
if (srs_config_pdu->resource_type == aperiodic) {
n_SRS = l/R;
}
else {
int8_t N_slot_frame = frame_parms->slots_per_frame;
n_SRS = ((N_slot_frame*frame_number + slot_number - T_offset)/T_SRS)*(N_symb_SRS/R)+(l/R);
}
uint16_t product_N_b = 1; /* for b_hop to b-1 */
for (unsigned int b_prime = b_hop; b_prime < B_SRS; b_prime++) { /* product for b_hop to b-1 */
if (b_prime != b_hop) {
product_N_b *= srs_bandwidth_config[C_SRS][b_prime][1];
}
}
if (N_b & 1) { /* Nb odd */
F_b = (N_b/2)*(n_SRS/product_N_b);
}
else { /* Nb even */
uint16_t product_N_b_B_SRS = product_N_b;
product_N_b_B_SRS *= srs_bandwidth_config[C_SRS][B_SRS][1]; /* product for b_hop to b */
F_b = (N_b/2)*((n_SRS%product_N_b_B_SRS)/product_N_b) + ((n_SRS%product_N_b_B_SRS)/2*product_N_b);
}
if (b <= b_hop) {
n_b[b] = (4 * n_RRC/m_SRS_b)%N_b;
}
else {
n_b[b] = (F_b + (4 * n_RRC/m_SRS_b))%N_b;
}
}
}
k_0_overbar_p = n_shift * N_SC_RB + K_TC_p;
k_0_p = k_0_overbar_p; /* it is the frequency-domain starting position */
for (int b = 0; b <= B_SRS; b++) {
k_0_p += K_TC * M_sc_b_SRS * n_b[b];
}
subcarrier = subcarrier_offset + k_0_p;
if (subcarrier>frame_parms->ofdm_symbol_size) {
subcarrier -= frame_parms->ofdm_symbol_size;
}
/* find index of table which is for this srs length */
unsigned int M_sc_b_SRS_index = 0;
while((ul_allocated_re[M_sc_b_SRS_index] != M_sc_b_SRS) && (M_sc_b_SRS_index < SRS_SB_CONF)){
M_sc_b_SRS_index++;
}
if (ul_allocated_re[M_sc_b_SRS_index] != M_sc_b_SRS) {
LOG_E(NR_PHY, "generate_srs: srs uplink allocation %d can not be found! \n", M_sc_b_SRS);
return (-1);
}
#if 0
char output_file[255];
char sequence_name[255];
sprintf(output_file, "rv_seq_%d_%d_%d.m", u, v_nu, ul_allocated_re[M_sc_b_SRS_index]);
sprintf(sequence_name, "rv_seq_%d_%d_%d", u, v_nu, ul_allocated_re[M_sc_b_SRS_index]);
write_output(output_file, sequence_name, rv_ul_ref_sig[u][v_nu][M_sc_b_SRS_index], ul_allocated_re[M_sc_b_SRS_index], 1, 1);
#ifdef SRS_DEBUG
LOG_I(NR_PHY,"============ port %d ============\n", p_index);
#endif
for (int k=0; k < M_sc_b_SRS; k++) {
uint16_t n_SRS_cs_i = (n_SRS_cs + (n_SRS_cs_max * (SRS_antenna_port[p_index] - 1000)/N_ap))%n_SRS_cs_max;
double alpha_i = 2 * M_PI * ((double)n_SRS_cs_i / (double)n_SRS_cs_max);
double real_shift = cos(alpha_i*k);
double imag_shift = sin(alpha_i*k);
/* cos(x + y) = cos(x)cos(y) - sin(x)sin(y) */
double real = ((real_shift*rv_ul_ref_sig[u][v_nu][M_sc_b_SRS_index][2*k]) - (imag_shift*rv_ul_ref_sig[u][v_nu][M_sc_b_SRS_index][2*k+1]))/sqrt(N_ap);
/* sin(x + y) = sin(x)cos(y) + cos(x)sin(y) */
double imag = ((imag_shift*rv_ul_ref_sig[u][v_nu][M_sc_b_SRS_index][2*k]) + (real_shift*rv_ul_ref_sig[u][v_nu][M_sc_b_SRS_index][2*k+1]))/sqrt(N_ap);
int32_t real_amp = ((int32_t)round((double) amp * real)) >> 15;
int32_t imag_amp = ((int32_t)round((double) amp * imag)) >> 15;
#if 0
printf("subcarrier %5d srs[%3d] r: %4d i: %4d reference[%d][%d][%d] r: %6d i: %6d\n", subcarrier, k, real_amp, imag_amp,
u, v_nu, M_sc_b_SRS_index,
rv_ul_ref_sig[u][v_nu][M_sc_b_SRS_index][2*k],
rv_ul_ref_sig[u][v_nu][M_sc_b_SRS_index][2*k+1]);
#ifdef SRS_DEBUG
LOG_I(NR_PHY,"n_SRS_cs_i = %i\n", n_SRS_cs_i);
LOG_I(NR_PHY,"alpha_i = %f\n", alpha_i);
#endif
txptr[subcarrier] = (real_amp & 0xFFFF) + ((imag_amp<<16)&0xFFFF0000);
for (int l_line = 0; l_line < N_symb_SRS; l_line++) {
if(nr_srs_info && p_index==0) {
nr_srs_info->sc_list[nr_srs_info->sc_list_length] = subcarrier;
nr_srs_info->sc_list_length++;
#ifdef SRS_DEBUG
LOG_I(NR_PHY,":::::::: OFDM symbol %d ::::::::\n", l0+l_line);
#endif
// Set group and sequence numbers (u,v) per OFDM symbol
uint16_t u = 0;
uint16_t v = 0;
switch(groupOrSequenceHopping) {
case neitherHopping:
u = n_ID_SRS%U_GROUP_NUMBER;
v = 0;
break;
case groupHopping:
u = group_number_hopping(slot_number, n_ID_SRS, l0, l_line);
v = 0;
break;
case sequenceHopping:
u = n_ID_SRS%U_GROUP_NUMBER;
v = sequence_number_hopping(slot_number, n_ID_SRS, M_sc_b_SRS, l0, l_line);
break;
default:
LOG_E(NR_PHY, "generate_srs: unknown hopping setting %d !\n", groupOrSequenceHopping);
return -1;
}
#ifdef SRS_DEBUG
int subcarrier_log = subcarrier-subcarrier_offset;
if(subcarrier_log < 0) {
subcarrier_log = subcarrier_log + frame_parms->ofdm_symbol_size;
}
if( subcarrier_log%12 == 0 ) {
LOG_I(NR_PHY,"------------ %d ------------\n", subcarrier_log/12);
}
LOG_I(NR_PHY,"(%d) \t%i\t%i\n", subcarrier_log, (int16_t)(real_amp&0xFFFF), (int16_t)(imag_amp&0xFFFF));
LOG_I(NR_PHY,"u = %i\n", u);
LOG_I(NR_PHY,"v = %i\n", v);
#endif
subcarrier += (K_TC); /* subcarrier increment */
// Compute the frequency position index n_b
uint16_t sum_n_b = 0;
for (int b = 0; b <= B_SRS; b++) {
n_b[b] = compute_n_b(frame_number, slot_number, frame_parms->slots_per_frame, N_symb_SRS, B_SRS,
C_SRS, b_hop, n_RRC, R, T_offset, T_SRS, srs_config_pdu->resource_type, l_line, b);
sum_n_b += n_b[b];
#ifdef SRS_DEBUG
LOG_I(NR_PHY,"n_b[%i] = %i\n", b, n_b[b]);
#endif
if (subcarrier >= frame_parms->ofdm_symbol_size) {
subcarrier=subcarrier-frame_parms->ofdm_symbol_size;
}
}
/* process next symbol */
//txptr = txptr + frame_parms->ofdm_symbol_size;
}
#ifdef SRS_DEBUG
LOG_I(NR_PHY,"sum_n_b = %i\n", sum_n_b);
#endif
return (0);
// Compute the frequency-domain starting position
uint8_t K_TC_p = 0;
if((n_SRS_cs >= n_SRS_cs_max/2)&&(n_SRS_cs < n_SRS_cs_max)&&(N_ap == 4) && ((SRS_antenna_port[p_index] == 1001) || (SRS_antenna_port[p_index] == 1003))) {
K_TC_p = (K_TC_overbar + K_TC/2)%K_TC;
} else {
K_TC_p = K_TC_overbar;
}
uint8_t k_l_offset = 0; // If the SRS is configured by the IE SRS-PosResource-r16, the quantity k_l_offset is
// given by TS 38.211 - Table 6.4.1.4.3-2, otherwise k_l_offset = 0.
uint8_t k_0_overbar_p = (n_shift*N_SC_RB + (K_TC_p+k_l_offset))%K_TC;
uint8_t k_0_p = k_0_overbar_p + K_TC*M_sc_b_SRS*sum_n_b;
#ifdef SRS_DEBUG
LOG_I(NR_PHY,"K_TC_p = %i\n", K_TC_p);
LOG_I(NR_PHY,"k_0_overbar_p = %i\n", k_0_overbar_p);
LOG_I(NR_PHY,"k_0_p = %i\n", k_0_p);
#endif
uint16_t subcarrier = subcarrier_offset + k_0_p;
if (subcarrier>frame_parms->ofdm_symbol_size) {
subcarrier -= frame_parms->ofdm_symbol_size;
}
uint16_t l_line_offset = l_line*frame_parms->ofdm_symbol_size;
// For each port, and for each OFDM symbol, here it is computed and mapped an SRS sequence with M_sc_b_SRS symbols
for (int k = 0; k < M_sc_b_SRS; k++) {
double shift_real = cos(alpha_i * k);
double shift_imag = sin(alpha_i * k);
int16_t r_overbar_real = rv_ul_ref_sig[u][v][M_sc_b_SRS_index][k<<1];
int16_t r_overbar_imag = rv_ul_ref_sig[u][v][M_sc_b_SRS_index][(k<<1)+1];
// cos(x+y) = cos(x)cos(y) - sin(x)sin(y)
double r_real = (shift_real*r_overbar_real - shift_imag*r_overbar_imag) / sqrt_N_ap;
// sin(x+y) = sin(x)cos(y) + cos(x)sin(y)
double r_imag = (shift_imag*r_overbar_real + shift_real*r_overbar_imag) / sqrt_N_ap;
int32_t r_real_amp = ((int32_t) round((double) amp * r_real)) >> 15;
int32_t r_imag_amp = ((int32_t) round((double) amp * r_imag)) >> 15;
#ifdef SRS_DEBUG
int subcarrier_log = subcarrier-subcarrier_offset;
if(subcarrier_log < 0) {
subcarrier_log = subcarrier_log + frame_parms->ofdm_symbol_size;
}
if(subcarrier_log%12 == 0) {
LOG_I(NR_PHY,"------------ %d ------------\n", subcarrier_log/12);
}
LOG_I(NR_PHY,"(%d) \t%i\t%i\n", subcarrier_log, (int16_t)(r_real_amp&0xFFFF), (int16_t)(r_imag_amp&0xFFFF));
#endif
txdataF[p_index][symbol_offset+l_line_offset+subcarrier] = (r_real_amp & 0xFFFF) + ((r_imag_amp<<16)&0xFFFF0000);
if(nr_srs_info && p_index==0 && l_line==0) {
nr_srs_info->sc_list[nr_srs_info->sc_list_length] = subcarrier;
nr_srs_info->sc_list_length++;
}
// Subcarrier increment
subcarrier += K_TC;
if (subcarrier >= frame_parms->ofdm_symbol_size) {
subcarrier=subcarrier-frame_parms->ofdm_symbol_size;
}
} // for (int k = 0; k < M_sc_b_SRS; k++)
} // for (int l_line = 0; l_line < N_symb_SRS; l_line++)
} // for (int p_index = 0; p_index < N_ap; p_index++)
return 0;
}
/*******************************************************************
openair1/PHY/NR_UE_TRANSPORT/srs_modulation_nr.h
+7
View File
@@ -131,6 +131,13 @@ EXTERN const uint16_t srs_periodicity[SRS_PERIODICITY]
#endif
;
// TS 38.211 - Table 6.4.1.4.2-1
EXTERN const uint16_t srs_max_number_cs[3]
#ifdef INIT_VARIABLES_SRS_MODULATION_NR_H
= {8, 12, 6}
#endif
;
/*************** FUNCTIONS *****************************************/
/** \brief This function generates the sounding reference symbol (SRS) for the uplink according to 38.211 6.4.1.4 Sounding reference signal