void srslte_agc_process(srslte_agc_t *q, cf_t *signal, uint32_t len) {
float gain_db = 10*log10(q->gain);
float gain_uhd_db = 1.0;
//float gain_uhd = 1.0;
float y = 0;
// Apply current gain to input signal
if (!q->uhd_handler) {
srslte_vec_sc_prod_cfc(signal, q->gain, signal, len);
} else {
if (q->gain < 1) {
q->gain = 1.0;
}
if (isinf(gain_db) || isnan(gain_db)) {
q->gain = 10.0;
} else {
gain_uhd_db = q->set_gain_callback(q->uhd_handler, gain_db);
q->gain = pow(10, gain_uhd_db/10);
}
}
float *t;
switch(q->mode) {
case SRSLTE_AGC_MODE_ENERGY:
y = sqrtf(crealf(srslte_vec_dot_prod_conj_ccc(signal, signal, len))/len);
break;
case SRSLTE_AGC_MODE_PEAK_AMPLITUDE:
t = (float*) signal;
y = t[srslte_vec_max_fi(t, 2*len)];// take only positive max to avoid abs() (should be similar)
break;
default:
fprintf(stderr, "Unsupported AGC mode\n");
return;
}
if (q->nof_frames > 0) {
q->y_tmp[q->frame_cnt++] = y;
if (q->frame_cnt == q->nof_frames) {
q->frame_cnt = 0;
switch(q->mode) {
case SRSLTE_AGC_MODE_ENERGY:
y = srslte_vec_acc_ff(q->y_tmp, q->nof_frames)/q->nof_frames;
break;
case SRSLTE_AGC_MODE_PEAK_AMPLITUDE:
y = q->y_tmp[srslte_vec_max_fi(q->y_tmp, q->nof_frames)];
break;
default:
fprintf(stderr, "Unsupported AGC mode\n");
return;
}
}
}
double gg = 1.0;
if (q->isfirst) {
q->y_out = y;
q->isfirst = false;
} else {
if (q->frame_cnt == 0) {
q->y_out = (1-q->bandwidth) * q->y_out + q->bandwidth * y;
if (!q->lock) {
gg = expf(-0.5*q->bandwidth*logf(q->y_out/q->target));
q->gain *= gg;
}
INFO("AGC gain: %.2f (%.2f) y_out=%.3f, y=%.3f target=%.1f gg=%.2f\n", gain_db, gain_uhd_db, q->y_out, y, q->target, gg);
}
}
}
int srslte_prach_detect_offset(srslte_prach_t *p,
uint32_t freq_offset,
cf_t *signal,
uint32_t sig_len,
uint32_t *indices,
float *t_offsets,
float *peak_to_avg,
uint32_t *n_indices)
{
int ret = SRSLTE_ERROR;
if(p != NULL &&
signal != NULL &&
sig_len > 0 &&
indices != NULL)
{
if(sig_len < p->N_ifft_prach){
fprintf(stderr, "srslte_prach_detect: Signal length is %d and should be %d\n", sig_len, p->N_ifft_prach);
return SRSLTE_ERROR_INVALID_INPUTS;
}
// FFT incoming signal
srslte_dft_run(p->fft, signal, p->signal_fft);
*n_indices = 0;
// Extract bins of interest
uint32_t N_rb_ul = srslte_nof_prb(p->N_ifft_ul);
uint32_t k_0 = freq_offset*N_RB_SC - N_rb_ul*N_RB_SC/2 + p->N_ifft_ul/2;
uint32_t K = DELTA_F/DELTA_F_RA;
uint32_t begin = PHI + (K*k_0) + (K/2);
memcpy(p->prach_bins, &p->signal_fft[begin], p->N_zc*sizeof(cf_t));
for(int i=0;i<p->N_roots;i++){
cf_t *root_spec = p->dft_seqs[p->root_seqs_idx[i]];
srslte_vec_prod_conj_ccc(p->prach_bins, root_spec, p->corr_spec, p->N_zc);
srslte_dft_run(p->zc_ifft, p->corr_spec, p->corr_spec);
srslte_vec_abs_square_cf(p->corr_spec, p->corr, p->N_zc);
float corr_ave = srslte_vec_acc_ff(p->corr, p->N_zc)/p->N_zc;
uint32_t winsize = 0;
if(p->N_cs != 0){
winsize = p->N_cs;
}else{
winsize = p->N_zc;
}
uint32_t n_wins = p->N_zc/winsize;
float max_peak = 0;
for(int j=0;j<n_wins;j++) {
uint32_t start = (p->N_zc-(j*p->N_cs))%p->N_zc;
uint32_t end = start+winsize;
if (end>p->deadzone) {
end-=p->deadzone;
}
start += p->deadzone;
p->peak_values[j] = 0;
for(int k=start;k<end;k++) {
if(p->corr[k] > p->peak_values[j]) {
p->peak_values[j] = p->corr[k];
p->peak_offsets[j] = k-start;
if (p->peak_values[j] > max_peak) {
max_peak = p->peak_values[j];
}
}
}
}
if (max_peak > p->detect_factor*corr_ave) {
for (int j=0;j<n_wins;j++) {
if(p->peak_values[j] > p->detect_factor*corr_ave)
{
printf("ncs=%d, nzc=%d, nwins=%d, Nroot=%d, i=%d, j=%d, start=%d, peak_value=%f, peak_offset=%d, tseq=%f\n",
p->N_cs, p->N_zc, n_wins, p->N_roots, i, j, (p->N_zc-(j*p->N_cs))%p->N_zc, p->peak_values[j],
p->peak_offsets[j], p->T_seq*1e6);
memcpy(save_corr, p->corr, p->N_zc*sizeof(float));
if (indices) {
indices[*n_indices] = (i*n_wins)+j;
}
if (peak_to_avg) {
peak_to_avg[*n_indices] = p->peak_values[j]/corr_ave;
}
if (t_offsets) {
t_offsets[*n_indices] = (float) p->peak_offsets[j]*p->T_seq/p->N_zc;
}
(*n_indices)++;
}
}
}
}
ret = SRSLTE_SUCCESS;
}
return ret;
}
