void srslte_interp_linear_offset(srslte_interp_lin_t *q, cf_t *input, cf_t *output,
uint32_t off_st, uint32_t off_end)
{
uint32_t i, j;
cf_t diff;
i=0;
for (j=0;j<off_st;j++) {
output[j] = input[i] + (j+1) * (input[i+1]-input[i]) / q->M;
}
srslte_vec_sub_ccc(&input[1], input, q->diff_vec, (q->vector_len-1));
srslte_vec_sc_prod_cfc(q->diff_vec, (float) 1/q->M, q->diff_vec, q->vector_len-1);
for (i=0;i<q->vector_len-1;i++) {
for (j=0;j<q->M;j++) {
output[i*q->M+j+off_st] = input[i];
q->diff_vec2[i*q->M+j] = q->diff_vec[i];
}
srslte_vec_prod_cfc(&q->diff_vec2[i*q->M],q->ramp,&q->diff_vec2[i*q->M],q->M);
}
srslte_vec_sum_ccc(&output[off_st], q->diff_vec2, &output[off_st], q->M*(q->vector_len-1));
if (q->vector_len > 1) {
diff = input[q->vector_len-1]-input[q->vector_len-2];
for (j=0;j<off_end;j++) {
output[i*q->M+j+off_st] = input[i] + j * diff / q->M;
}
}
}
void srslte_interp_linear_vector(srslte_interp_linsrslte_vec_t *q, cf_t *in0, cf_t *in1, cf_t *between, uint32_t M)
{
uint32_t i;
srslte_vec_sub_ccc(in1, in0, q->diff_vec, q->vector_len);
srslte_vec_sc_prod_cfc(q->diff_vec, (float) 1/M, q->diff_vec, q->vector_len);
srslte_vec_sum_ccc(in0, q->diff_vec, between, q->vector_len);
for (i=0;i<M-1;i++) {
srslte_vec_sum_ccc(between, q->diff_vec, &between[q->vector_len], q->vector_len);
between += q->vector_len;
}
}
/* input points to beginning of last OFDM symbol of slot 0 of subframe 0 or 5
* It must be called after calling srslte_pss_cfo_compute() with filter enabled
*/
void srslte_pss_sic(srslte_pss_t *q, cf_t *input) {
if (q->chest_on_filter) {
bzero(q->tmp_fft, sizeof(cf_t)*q->fft_size);
// Pass transmitted PSS sequence through the channel
srslte_vec_prod_ccc(q->pss_signal_freq[q->N_id_2], q->tmp_ce, &q->tmp_fft[(q->fft_size-SRSLTE_PSS_LEN)/2], SRSLTE_PSS_LEN);
// Get time-domain version of the received PSS
srslte_dft_run_c(&q->idftp_input, q->tmp_fft, q->tmp_fft2);
// Substract received PSS from this N_id_2 from the input signal
srslte_vec_sc_prod_cfc(q->tmp_fft2, 1.0/q->fft_size, q->tmp_fft2, q->fft_size);
srslte_vec_sub_ccc(input, q->tmp_fft2, input, q->fft_size);
} else {
ERROR("Error calling srslte_pss_sic(): need to enable channel estimation on filtering\n");
}
}
