int srslte_prach_init(srslte_prach_t *p,
uint32_t N_ifft_ul,
uint32_t preamble_format,
uint32_t root_seq_index,
bool high_speed_flag,
uint32_t zero_corr_zone_config)
{
int ret = SRSLTE_ERROR;
if(p != NULL &&
N_ifft_ul < 2049 &&
preamble_format < 4 && // Currently supporting formats 0-3
root_seq_index < MAX_ROOTS &&
zero_corr_zone_config < 16)
{
p->f = preamble_format;
p->rsi = root_seq_index;
p->hs = high_speed_flag;
p->zczc = zero_corr_zone_config;
// Determine N_zc and N_cs
if(4 == preamble_format){
p->N_zc = 139;
p->N_cs = prach_Ncs_format4[p->zczc];
}else{
p->N_zc = 839;
if(p->hs){
p->N_cs = prach_Ncs_restricted[p->zczc];
}else{
p->N_cs = prach_Ncs_unrestricted[p->zczc];
}
}
// Set up containers
p->prach_bins = srslte_vec_malloc(sizeof(cf_t)*p->N_zc);
p->corr_spec = srslte_vec_malloc(sizeof(cf_t)*p->N_zc);
p->corr = srslte_vec_malloc(sizeof(float)*p->N_zc);
// Set up ZC FFTS
p->zc_fft = (srslte_dft_plan_t*)srslte_vec_malloc(sizeof(srslte_dft_plan_t));
if(srslte_dft_plan(p->zc_fft, p->N_zc, SRSLTE_DFT_FORWARD, SRSLTE_DFT_COMPLEX)){
return SRSLTE_ERROR;
}
srslte_dft_plan_set_mirror(p->zc_fft, false);
srslte_dft_plan_set_norm(p->zc_fft, true);
p->zc_ifft = (srslte_dft_plan_t*)srslte_vec_malloc(sizeof(srslte_dft_plan_t));
if(srslte_dft_plan(p->zc_ifft, p->N_zc, SRSLTE_DFT_BACKWARD, SRSLTE_DFT_COMPLEX)){
return SRSLTE_ERROR;
}
srslte_dft_plan_set_mirror(p->zc_ifft, false);
srslte_dft_plan_set_norm(p->zc_ifft, true);
// Generate our 64 sequences
p->N_roots = 0;
srslte_prach_gen_seqs(p);
// Generate sequence FFTs
for(int i=0;i<N_SEQS;i++){
srslte_dft_run(p->zc_fft, p->seqs[i], p->dft_seqs[i]);
}
// Create our FFT objects and buffers
p->N_ifft_ul = N_ifft_ul;
if(4 == preamble_format){
p->N_ifft_prach = p->N_ifft_ul * DELTA_F/DELTA_F_RA_4;
}else{
p->N_ifft_prach = p->N_ifft_ul * DELTA_F/DELTA_F_RA;
}
p->ifft_in = (cf_t*)srslte_vec_malloc(p->N_ifft_prach*sizeof(cf_t));
p->ifft_out = (cf_t*)srslte_vec_malloc(p->N_ifft_prach*sizeof(cf_t));
p->ifft = (srslte_dft_plan_t*)srslte_vec_malloc(sizeof(srslte_dft_plan_t));
if(srslte_dft_plan(p->ifft, p->N_ifft_prach, SRSLTE_DFT_BACKWARD, SRSLTE_DFT_COMPLEX)) {
fprintf(stderr, "Error creating DFT plan\n");
return -1;
}
srslte_dft_plan_set_mirror(p->ifft, true);
srslte_dft_plan_set_norm(p->ifft, true);
p->fft = (srslte_dft_plan_t*)srslte_vec_malloc(sizeof(srslte_dft_plan_t));
if(srslte_dft_plan(p->fft, p->N_ifft_prach, SRSLTE_DFT_FORWARD, SRSLTE_DFT_COMPLEX)){
fprintf(stderr, "Error creating DFT plan\n");
return -1;
}
srslte_dft_plan_set_mirror(p->fft, true);
srslte_dft_plan_set_norm(p->fft, true);
p->N_seq = prach_Tseq[p->f]*p->N_ifft_ul/2048;
p->N_cp = prach_Tcp[p->f]*p->N_ifft_ul/2048;
ret = SRSLTE_SUCCESS;
} else {
fprintf(stderr, "Invalid parameters\n");
}
return ret;
}
int srslte_prach_init(srslte_prach_t *p,
uint32_t N_ifft_ul,
uint32_t config_idx,
uint32_t root_seq_index,
bool high_speed_flag,
uint32_t zero_corr_zone_config)
{
int ret = SRSLTE_ERROR;
if(p != NULL &&
N_ifft_ul < 2049 &&
config_idx < 16 &&
root_seq_index < MAX_ROOTS)
{
uint32_t preamble_format = srslte_prach_get_preamble_format(config_idx);
p->config_idx = config_idx;
p->f = preamble_format;
p->rsi = root_seq_index;
p->hs = high_speed_flag;
p->zczc = zero_corr_zone_config;
p->detect_factor = PRACH_DETECT_FACTOR;
// Determine N_zc and N_cs
if(4 == preamble_format){
if (p->zczc < 7) {
p->N_zc = 139;
p->N_cs = prach_Ncs_format4[p->zczc];
} else {
fprintf(stderr, "Invalid zeroCorrelationZoneConfig=%d for format4\n", p->zczc);
return SRSLTE_ERROR;
}
}else{
p->N_zc = 839;
if(p->hs){
if (p->zczc < 15) {
p->N_cs = prach_Ncs_restricted[p->zczc];
} else {
fprintf(stderr, "Invalid zeroCorrelationZoneConfig=%d for restricted set\n", p->zczc);
return SRSLTE_ERROR;
}
}else{
if (p->zczc < 16) {
p->N_cs = prach_Ncs_unrestricted[p->zczc];
} else {
fprintf(stderr, "Invalid zeroCorrelationZoneConfig=%d\n", p->zczc);
return SRSLTE_ERROR;
}
}
}
// Set up containers
p->prach_bins = srslte_vec_malloc(sizeof(cf_t)*p->N_zc);
p->corr_spec = srslte_vec_malloc(sizeof(cf_t)*p->N_zc);
p->corr = srslte_vec_malloc(sizeof(float)*p->N_zc);
// Set up ZC FFTS
p->zc_fft = (srslte_dft_plan_t*)srslte_vec_malloc(sizeof(srslte_dft_plan_t));
if(srslte_dft_plan(p->zc_fft, p->N_zc, SRSLTE_DFT_FORWARD, SRSLTE_DFT_COMPLEX)){
return SRSLTE_ERROR;
}
srslte_dft_plan_set_mirror(p->zc_fft, false);
srslte_dft_plan_set_norm(p->zc_fft, true);
p->zc_ifft = (srslte_dft_plan_t*)srslte_vec_malloc(sizeof(srslte_dft_plan_t));
if(srslte_dft_plan(p->zc_ifft, p->N_zc, SRSLTE_DFT_BACKWARD, SRSLTE_DFT_COMPLEX)){
return SRSLTE_ERROR;
}
srslte_dft_plan_set_mirror(p->zc_ifft, false);
srslte_dft_plan_set_norm(p->zc_ifft, false);
// Generate our 64 sequences
p->N_roots = 0;
srslte_prach_gen_seqs(p);
// Generate sequence FFTs
for(int i=0;i<N_SEQS;i++){
srslte_dft_run(p->zc_fft, p->seqs[i], p->dft_seqs[i]);
}
// Create our FFT objects and buffers
p->N_ifft_ul = N_ifft_ul;
if(4 == preamble_format){
p->N_ifft_prach = p->N_ifft_ul * DELTA_F/DELTA_F_RA_4;
}else{
p->N_ifft_prach = p->N_ifft_ul * DELTA_F/DELTA_F_RA;
}
/* The deadzone specifies the number of samples at the end of the correlation window
* that will be considered as belonging to the next preamble
*/
p->deadzone = 0;
/*
if(p->N_cs != 0) {
float samp_rate=15000*p->N_ifft_ul;
p->deadzone = (uint32_t) ceil((float) samp_rate/((float) p->N_zc*subcarrier_spacing));
}*/
p->ifft_in = (cf_t*)srslte_vec_malloc(p->N_ifft_prach*sizeof(cf_t));
p->ifft_out = (cf_t*)srslte_vec_malloc(p->N_ifft_prach*sizeof(cf_t));
p->ifft = (srslte_dft_plan_t*)srslte_vec_malloc(sizeof(srslte_dft_plan_t));
if(srslte_dft_plan(p->ifft, p->N_ifft_prach, SRSLTE_DFT_BACKWARD, SRSLTE_DFT_COMPLEX)) {
fprintf(stderr, "Error creating DFT plan\n");
return -1;
}
srslte_dft_plan_set_mirror(p->ifft, true);
srslte_dft_plan_set_norm(p->ifft, true);
p->fft = (srslte_dft_plan_t*)srslte_vec_malloc(sizeof(srslte_dft_plan_t));
if(srslte_dft_plan(p->fft, p->N_ifft_prach, SRSLTE_DFT_FORWARD, SRSLTE_DFT_COMPLEX)){
fprintf(stderr, "Error creating DFT plan\n");
return -1;
}
p->signal_fft = srslte_vec_malloc(sizeof(cf_t)*p->N_ifft_prach);
if (!p->signal_fft) {
fprintf(stderr, "Error allocating memory\n");
return -1;
}
srslte_dft_plan_set_mirror(p->fft, true);
srslte_dft_plan_set_norm(p->fft, false);
p->N_seq = prach_Tseq[p->f]*p->N_ifft_ul/2048;
p->N_cp = prach_Tcp[p->f]*p->N_ifft_ul/2048;
p->T_seq = prach_Tseq[p->f]*SRSLTE_LTE_TS;
ret = SRSLTE_SUCCESS;
} else {
fprintf(stderr, "Invalid parameters\n");
}
return ret;
}
