|
|
|
@ -137,15 +137,9 @@ int srslte_pss_synch_init_fft_offset_decim(srslte_pss_synch_t *q,
|
|
|
|
|
}
|
|
|
|
|
srslte_dft_plan_set_mirror(&q->dftp_input, true);
|
|
|
|
|
srslte_dft_plan_set_dc(&q->dftp_input, true);
|
|
|
|
|
srslte_dft_plan_set_norm(&q->dftp_input, true);
|
|
|
|
|
|
|
|
|
|
if (srslte_dft_plan(&q->idftp_input, fft_size, SRSLTE_DFT_BACKWARD, SRSLTE_DFT_COMPLEX)) {
|
|
|
|
|
fprintf(stderr, "Error creating DFT plan \n");
|
|
|
|
|
goto clean_and_exit;
|
|
|
|
|
}
|
|
|
|
|
srslte_dft_plan_set_mirror(&q->idftp_input, true);
|
|
|
|
|
srslte_dft_plan_set_dc(&q->idftp_input, true);
|
|
|
|
|
|
|
|
|
|
q->tmp_input = srslte_vec_malloc((buffer_size + frame_size*(q->decimate - 1)) * sizeof(cf_t));
|
|
|
|
|
q->tmp_input = srslte_vec_malloc((buffer_size + frame_size*(q->decimate - 1)) * sizeof(cf_t));
|
|
|
|
|
if (!q->tmp_input) {
|
|
|
|
|
fprintf(stderr, "Error allocating memory\n");
|
|
|
|
|
goto clean_and_exit;
|
|
|
|
@ -173,7 +167,7 @@ int srslte_pss_synch_init_fft_offset_decim(srslte_pss_synch_t *q,
|
|
|
|
|
}
|
|
|
|
|
bzero(q->conv_output_abs, sizeof(float) * buffer_size);
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
for (N_id_2=0;N_id_2<3;N_id_2++) {
|
|
|
|
|
q->pss_signal_time[N_id_2] = srslte_vec_malloc(buffer_size * sizeof(cf_t));
|
|
|
|
|
if (!q->pss_signal_time[N_id_2]) {
|
|
|
|
@ -184,14 +178,14 @@ int srslte_pss_synch_init_fft_offset_decim(srslte_pss_synch_t *q,
|
|
|
|
|
if (srslte_pss_synch_init_N_id_2(q->pss_signal_freq[N_id_2], q->pss_signal_time[N_id_2], N_id_2, fft_size, offset)) {
|
|
|
|
|
fprintf(stderr, "Error initiating PSS detector for N_id_2=%d fft_size=%d\n", N_id_2, fft_size);
|
|
|
|
|
goto clean_and_exit;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
bzero(&q->pss_signal_time[N_id_2][q->fft_size], q->frame_size * sizeof(cf_t));
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
#ifdef CONVOLUTION_FFT
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
for(N_id_2=0; N_id_2<3; N_id_2++)
|
|
|
|
|
q->pss_signal_freq_full[N_id_2] = srslte_vec_malloc(buffer_size * sizeof(cf_t));
|
|
|
|
|
q->pss_signal_freq_full[N_id_2] = srslte_vec_malloc(buffer_size * sizeof(cf_t));
|
|
|
|
|
|
|
|
|
|
if (srslte_conv_fft_cc_init(&q->conv_fft, frame_size, fft_size)) {
|
|
|
|
|
fprintf(stderr, "Error initiating convolution FFT\n");
|
|
|
|
@ -200,15 +194,15 @@ int srslte_pss_synch_init_fft_offset_decim(srslte_pss_synch_t *q,
|
|
|
|
|
for(int i=0; i<3; i++) {
|
|
|
|
|
srslte_dft_run_c(&q->conv_fft.filter_plan, q->pss_signal_time[i], q->pss_signal_freq_full[i]);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
srslte_pss_synch_reset(q);
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
ret = SRSLTE_SUCCESS;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
clean_and_exit:
|
|
|
|
|
clean_and_exit:
|
|
|
|
|
if (ret == SRSLTE_ERROR) {
|
|
|
|
|
srslte_pss_synch_free(q);
|
|
|
|
|
}
|
|
|
|
@ -304,7 +298,7 @@ void srslte_pss_synch_free(srslte_pss_synch_t *q) {
|
|
|
|
|
}
|
|
|
|
|
#ifdef CONVOLUTION_FFT
|
|
|
|
|
srslte_conv_fft_cc_free(&q->conv_fft);
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
#endif
|
|
|
|
|
if (q->tmp_input) {
|
|
|
|
|
free(q->tmp_input);
|
|
|
|
@ -318,10 +312,9 @@ void srslte_pss_synch_free(srslte_pss_synch_t *q) {
|
|
|
|
|
if (q->conv_output_avg) {
|
|
|
|
|
free(q->conv_output_avg);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
srslte_dft_plan_free(&q->dftp_input);
|
|
|
|
|
srslte_dft_plan_free(&q->idftp_input);
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
if(q->decimate > 1)
|
|
|
|
|
{
|
|
|
|
|
srslte_filt_decim_cc_free(&q->filter);
|
|
|
|
@ -330,7 +323,7 @@ void srslte_pss_synch_free(srslte_pss_synch_t *q) {
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
bzero(q, sizeof(srslte_pss_synch_t));
|
|
|
|
|
bzero(q, sizeof(srslte_pss_synch_t));
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
@ -386,7 +379,7 @@ void srslte_pss_put_slot(cf_t *pss_signal, cf_t *slot, uint32_t nof_prb, srslte_
|
|
|
|
|
void srslte_pss_get_slot(cf_t *slot, cf_t *pss_signal, uint32_t nof_prb, srslte_cp_t cp) {
|
|
|
|
|
int k;
|
|
|
|
|
k = (SRSLTE_CP_NSYMB(cp) - 1) * nof_prb * SRSLTE_NRE + nof_prb * SRSLTE_NRE / 2 - 31;
|
|
|
|
|
memcpy(pss_signal, &slot[k], SRSLTE_PSS_LEN * sizeof(cf_t));
|
|
|
|
|
memcpy(pss_signal, &slot[k], SRSLTE_PSS_LEN * sizeof(cf_t));
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
@ -405,34 +398,34 @@ int srslte_pss_synch_set_N_id_2(srslte_pss_synch_t *q, uint32_t N_id_2) {
|
|
|
|
|
/* Sets the weight factor alpha for the exponential moving average of the PSS correlation output
|
|
|
|
|
*/
|
|
|
|
|
void srslte_pss_synch_set_ema_alpha(srslte_pss_synch_t *q, float alpha) {
|
|
|
|
|
q->ema_alpha = alpha;
|
|
|
|
|
q->ema_alpha = alpha;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/** Performs time-domain PSS correlation.
|
|
|
|
|
/** Performs time-domain PSS correlation.
|
|
|
|
|
* Returns the index of the PSS correlation peak in a subframe.
|
|
|
|
|
* The frame starts at corr_peak_pos-subframe_size/2.
|
|
|
|
|
* The value of the correlation is stored in corr_peak_value.
|
|
|
|
|
*
|
|
|
|
|
* Input buffer must be subframe_size long.
|
|
|
|
|
*/
|
|
|
|
|
int srslte_pss_synch_find_pss(srslte_pss_synch_t *q, cf_t *input, float *corr_peak_value)
|
|
|
|
|
int srslte_pss_synch_find_pss(srslte_pss_synch_t *q, cf_t *input, float *corr_peak_value)
|
|
|
|
|
{
|
|
|
|
|
int ret = SRSLTE_ERROR_INVALID_INPUTS;
|
|
|
|
|
|
|
|
|
|
if (q != NULL &&
|
|
|
|
|
|
|
|
|
|
if (q != NULL &&
|
|
|
|
|
input != NULL)
|
|
|
|
|
{
|
|
|
|
|
|
|
|
|
|
uint32_t corr_peak_pos;
|
|
|
|
|
uint32_t conv_output_len;
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
if (!srslte_N_id_2_isvalid(q->N_id_2)) {
|
|
|
|
|
fprintf(stderr, "Error finding PSS peak, Must set N_id_2 first\n");
|
|
|
|
|
return SRSLTE_ERROR;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Correlate input with PSS sequence
|
|
|
|
|
*
|
|
|
|
|
*
|
|
|
|
|
* We do not reverse time-domain PSS signal because it's conjugate is symmetric.
|
|
|
|
|
* The conjugate operation on pss_signal_time has been done in srslte_pss_synch_init_N_id_2
|
|
|
|
|
* This is why we can use FFT-based convolution
|
|
|
|
@ -449,7 +442,7 @@ int srslte_pss_synch_find_pss(srslte_pss_synch_t *q, cf_t *input, float *corr_pe
|
|
|
|
|
{
|
|
|
|
|
conv_output_len = srslte_conv_fft_cc_run_opt(&q->conv_fft, q->tmp_input, q->pss_signal_freq_full[q->N_id_2], q->conv_output);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
#else
|
|
|
|
|
conv_output_len = srslte_conv_cc(input, q->pss_signal_time[q->N_id_2], q->conv_output, q->frame_size, q->fft_size);
|
|
|
|
|
#endif
|
|
|
|
@ -457,19 +450,19 @@ int srslte_pss_synch_find_pss(srslte_pss_synch_t *q, cf_t *input, float *corr_pe
|
|
|
|
|
for (int i=0;i<q->frame_size;i++) {
|
|
|
|
|
q->conv_output[i] = srslte_vec_dot_prod_ccc(q->pss_signal_time[q->N_id_2], &input[i], q->fft_size);
|
|
|
|
|
}
|
|
|
|
|
conv_output_len = q->frame_size;
|
|
|
|
|
conv_output_len = q->frame_size;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
#ifdef SRSLTE_PSS_ABS_SQUARE
|
|
|
|
|
srslte_vec_abs_square_cf(q->conv_output, q->conv_output_abs, conv_output_len-1);
|
|
|
|
|
#else
|
|
|
|
|
srslte_vec_abs_cf(q->conv_output, q->conv_output_abs, conv_output_len-1);
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
if (q->ema_alpha < 1.0 && q->ema_alpha > 0.0) {
|
|
|
|
|
srslte_vec_sc_prod_fff(q->conv_output_abs, q->ema_alpha, q->conv_output_abs, conv_output_len-1);
|
|
|
|
|
srslte_vec_sc_prod_fff(q->conv_output_avg, 1-q->ema_alpha, q->conv_output_avg, conv_output_len-1);
|
|
|
|
|
srslte_vec_sc_prod_fff(q->conv_output_abs, q->ema_alpha, q->conv_output_abs, conv_output_len-1);
|
|
|
|
|
srslte_vec_sc_prod_fff(q->conv_output_avg, 1-q->ema_alpha, q->conv_output_avg, conv_output_len-1);
|
|
|
|
|
|
|
|
|
|
srslte_vec_sum_fff(q->conv_output_abs, q->conv_output_avg, q->conv_output_avg, conv_output_len-1);
|
|
|
|
|
} else {
|
|
|
|
@ -477,43 +470,43 @@ int srslte_pss_synch_find_pss(srslte_pss_synch_t *q, cf_t *input, float *corr_pe
|
|
|
|
|
}
|
|
|
|
|
/* Find maximum of the absolute value of the correlation */
|
|
|
|
|
corr_peak_pos = srslte_vec_max_fi(q->conv_output_avg, conv_output_len-1);
|
|
|
|
|
|
|
|
|
|
// save absolute value
|
|
|
|
|
|
|
|
|
|
// save absolute value
|
|
|
|
|
q->peak_value = q->conv_output_avg[corr_peak_pos];
|
|
|
|
|
|
|
|
|
|
#ifdef SRSLTE_PSS_RETURN_PSR
|
|
|
|
|
|
|
|
|
|
#ifdef SRSLTE_PSS_RETURN_PSR
|
|
|
|
|
// Find second side lobe
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
// Find end of peak lobe to the right
|
|
|
|
|
int pl_ub = corr_peak_pos+1;
|
|
|
|
|
while(q->conv_output_avg[pl_ub+1] <= q->conv_output_avg[pl_ub] && pl_ub < conv_output_len) {
|
|
|
|
|
pl_ub ++;
|
|
|
|
|
pl_ub ++;
|
|
|
|
|
}
|
|
|
|
|
// Find end of peak lobe to the left
|
|
|
|
|
int pl_lb;
|
|
|
|
|
int pl_lb;
|
|
|
|
|
if (corr_peak_pos > 2) {
|
|
|
|
|
pl_lb = corr_peak_pos-1;
|
|
|
|
|
while(q->conv_output_avg[pl_lb-1] <= q->conv_output_avg[pl_lb] && pl_lb > 1) {
|
|
|
|
|
pl_lb --;
|
|
|
|
|
}
|
|
|
|
|
pl_lb --;
|
|
|
|
|
}
|
|
|
|
|
} else {
|
|
|
|
|
pl_lb = 0;
|
|
|
|
|
pl_lb = 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
int sl_distance_right = conv_output_len-1-pl_ub;
|
|
|
|
|
int sl_distance_right = conv_output_len-1-pl_ub;
|
|
|
|
|
if (sl_distance_right < 0) {
|
|
|
|
|
sl_distance_right = 0;
|
|
|
|
|
sl_distance_right = 0;
|
|
|
|
|
}
|
|
|
|
|
int sl_distance_left = pl_lb;
|
|
|
|
|
|
|
|
|
|
int sl_distance_left = pl_lb;
|
|
|
|
|
|
|
|
|
|
int sl_right = pl_ub+srslte_vec_max_fi(&q->conv_output_avg[pl_ub], sl_distance_right);
|
|
|
|
|
int sl_left = srslte_vec_max_fi(q->conv_output_avg, sl_distance_left);
|
|
|
|
|
float side_lobe_value = SRSLTE_MAX(q->conv_output_avg[sl_right], q->conv_output_avg[sl_left]);
|
|
|
|
|
int sl_left = srslte_vec_max_fi(q->conv_output_avg, sl_distance_left);
|
|
|
|
|
float side_lobe_value = SRSLTE_MAX(q->conv_output_avg[sl_right], q->conv_output_avg[sl_left]);
|
|
|
|
|
if (corr_peak_value) {
|
|
|
|
|
*corr_peak_value = q->conv_output_avg[corr_peak_pos]/side_lobe_value;
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
if (*corr_peak_value < 10)
|
|
|
|
|
DEBUG("peak_pos=%2d, pl_ub=%2d, pl_lb=%2d, sl_right: %2d, sl_left: %2d, PSR: %.2f/%.2f=%.2f\n", corr_peak_pos, pl_ub, pl_lb,
|
|
|
|
|
DEBUG("peak_pos=%2d, pl_ub=%2d, pl_lb=%2d, sl_right: %2d, sl_left: %2d, PSR: %.2f/%.2f=%.2f\n", corr_peak_pos, pl_ub, pl_lb,
|
|
|
|
|
sl_right,sl_left, q->conv_output_avg[corr_peak_pos], side_lobe_value,*corr_peak_value);
|
|
|
|
|
}
|
|
|
|
|
#else
|
|
|
|
@ -521,7 +514,7 @@ int srslte_pss_synch_find_pss(srslte_pss_synch_t *q, cf_t *input, float *corr_pe
|
|
|
|
|
*corr_peak_value = q->conv_output_avg[corr_peak_pos];
|
|
|
|
|
}
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
if(q->decimate >1)
|
|
|
|
|
{
|
|
|
|
|
int decimation_correction = (q->filter.num_taps - 2);
|
|
|
|
@ -531,23 +524,23 @@ int srslte_pss_synch_find_pss(srslte_pss_synch_t *q, cf_t *input, float *corr_pe
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
if (q->frame_size >= q->fft_size) {
|
|
|
|
|
ret = (int) corr_peak_pos;
|
|
|
|
|
ret = (int) corr_peak_pos;
|
|
|
|
|
} else {
|
|
|
|
|
ret = (int) corr_peak_pos + q->fft_size;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Computes frequency-domain channel estimation of the PSS symbol
|
|
|
|
|
* input signal is in the time-domain.
|
|
|
|
|
* ce is the returned frequency-domain channel estimates.
|
|
|
|
|
/* Computes frequency-domain channel estimation of the PSS symbol
|
|
|
|
|
* input signal is in the time-domain.
|
|
|
|
|
* ce is the returned frequency-domain channel estimates.
|
|
|
|
|
*/
|
|
|
|
|
int srslte_pss_synch_chest(srslte_pss_synch_t *q, cf_t *input, cf_t ce[SRSLTE_PSS_LEN]) {
|
|
|
|
|
int ret = SRSLTE_ERROR_INVALID_INPUTS;
|
|
|
|
|
cf_t input_fft[SRSLTE_SYMBOL_SZ_MAX];
|
|
|
|
|
|
|
|
|
|
if (q != NULL &&
|
|
|
|
|
if (q != NULL &&
|
|
|
|
|
input != NULL)
|
|
|
|
|
{
|
|
|
|
|
|
|
|
|
@ -555,46 +548,31 @@ int srslte_pss_synch_chest(srslte_pss_synch_t *q, cf_t *input, cf_t ce[SRSLTE_PS
|
|
|
|
|
fprintf(stderr, "Error finding PSS peak, Must set N_id_2 first\n");
|
|
|
|
|
return SRSLTE_ERROR;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
/* Transform to frequency-domain */
|
|
|
|
|
srslte_dft_run_c(&q->dftp_input, input, input_fft);
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
/* Compute channel estimate taking the PSS sequence as reference */
|
|
|
|
|
srslte_vec_prod_conj_ccc(&input_fft[(q->fft_size-SRSLTE_PSS_LEN)/2], q->pss_signal_freq[q->N_id_2], ce, SRSLTE_PSS_LEN);
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
ret = SRSLTE_SUCCESS;
|
|
|
|
|
}
|
|
|
|
|
return ret;
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#define CLEAN_NOISE_DFT
|
|
|
|
|
//#define PSS_CFO_FREQ
|
|
|
|
|
/* Returns the CFO estimation given a PSS received sequence
|
|
|
|
|
*
|
|
|
|
|
* Source: An Efficient CFO Estimation Algorithm for the Downlink of 3GPP-LTE
|
|
|
|
|
* Feng Wang and Yu Zhu
|
|
|
|
|
*/
|
|
|
|
|
float srslte_pss_synch_cfo_compute(srslte_pss_synch_t* q, cf_t *pss_recv) {
|
|
|
|
|
cf_t y0, y1;
|
|
|
|
|
|
|
|
|
|
#ifdef PSS_CFO_FREQ
|
|
|
|
|
|
|
|
|
|
srslte_vec_prod_conj_ccc(&q->tmp_fft[q->fft_size/2-SRSLTE_PSS_LEN/2], q->pss_signal_freq[q->N_id_2], q->yr, SRSLTE_PSS_LEN);
|
|
|
|
|
y0 = srslte_vec_acc_cc(q->yr, SRSLTE_PSS_LEN/2);
|
|
|
|
|
y1 = srslte_vec_acc_cc(&q->yr[SRSLTE_PSS_LEN/2], SRSLTE_PSS_LEN/2);
|
|
|
|
|
|
|
|
|
|
#else
|
|
|
|
|
#ifdef CLEAN_NOISE_DFT
|
|
|
|
|
// Eliminate noise
|
|
|
|
|
srslte_dft_run_c(&q->dftp_input, pss_recv, q->tmp_fft);
|
|
|
|
|
bzero(q->tmp_fft, sizeof(cf_t)*(q->fft_size/2-SRSLTE_PSS_LEN/2));
|
|
|
|
|
bzero(&q->tmp_fft[q->fft_size/2+SRSLTE_PSS_LEN/2], sizeof(cf_t)*(q->fft_size/2-SRSLTE_PSS_LEN/2));
|
|
|
|
|
srslte_dft_run_c(&q->idftp_input, q->tmp_fft, pss_recv);
|
|
|
|
|
#endif
|
|
|
|
|
cf_t y0, y1, yr;
|
|
|
|
|
|
|
|
|
|
y0 = srslte_vec_dot_prod_ccc(q->pss_signal_time[q->N_id_2], pss_recv, q->fft_size/2);
|
|
|
|
|
y1 = srslte_vec_dot_prod_ccc(&q->pss_signal_time[q->N_id_2][q->fft_size/2], &pss_recv[q->fft_size/2], q->fft_size/2);
|
|
|
|
|
#endif
|
|
|
|
|
return carg(conjf(y0) * y1)/M_PI;
|
|
|
|
|
|
|
|
|
|
yr = conjf(y0) * y1;
|
|
|
|
|
|
|
|
|
|
return atan2f(__imag__ yr, __real__ yr) / M_PI;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|