Commit eab6379b authored by Thomas Schlichter's avatar Thomas Schlichter 🇩🇪
Browse files

gNB: cut OFDM symbol for PUSCH reception within 1/8th of CP to avoid ISI

parent 97ed2dfe
......@@ -468,10 +468,12 @@ int nr_slot_fep_ul(NR_DL_FRAME_PARMS *frame_parms,
slot_offset = frame_parms->get_samples_slot_timestamp(Ns,frame_parms,0);
if(symbol == 0)
rxdata_offset = slot_offset + nb_prefix_samples0 - SOFFSET;
else
rxdata_offset = slot_offset + nb_prefix_samples0 + (symbol * (frame_parms->ofdm_symbol_size + nb_prefix_samples)) - SOFFSET;
// offset of first OFDM symbol
rxdata_offset = slot_offset + nb_prefix_samples0 - SOFFSET;
// offset of n-th OFDM symbol
rxdata_offset += symbol * (frame_parms->ofdm_symbol_size + nb_prefix_samples);
// use OFDM symbol from within 1/8th of the CP to avoid ISI
rxdata_offset -= nb_prefix_samples / 8;
if(sample_offset>rxdata_offset) {
memcpy1((void *)tmp_dft_in,
......
......@@ -37,22 +37,20 @@
int nr_est_timing_advance_pusch(PHY_VARS_gNB* gNB, int UE_id)
{
int temp, i, aa, max_pos = 0, max_val = 0;
short Re, Im;
uint8_t cyclic_shift = 0;
int i, aa, max_pos = 0, max_val = 0;
NR_DL_FRAME_PARMS *frame_parms = &gNB->frame_parms;
NR_gNB_PUSCH *gNB_pusch_vars = gNB->pusch_vars[UE_id];
int32_t **ul_ch_estimates_time = gNB_pusch_vars->ul_ch_estimates_time;
int sync_pos = (frame_parms->ofdm_symbol_size - cyclic_shift*frame_parms->ofdm_symbol_size/12) % (frame_parms->ofdm_symbol_size);
int sync_pos = frame_parms->nb_prefix_samples / 8;
for (i = 0; i < frame_parms->ofdm_symbol_size; i++) {
temp = 0;
int temp = 0;
for (aa = 0; aa < frame_parms->nb_antennas_rx; aa++) {
Re = ((int16_t*)ul_ch_estimates_time[aa])[(i<<1)];
Im = ((int16_t*)ul_ch_estimates_time[aa])[1+(i<<1)];
short Re = ((int16_t*)ul_ch_estimates_time[aa])[(i<<1)];
short Im = ((int16_t*)ul_ch_estimates_time[aa])[1+(i<<1)];
temp += (Re*Re/2) + (Im*Im/2);
}
......
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