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5G NR: move CIR peak to 0

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The rotation compensating the shifted OFDM position _before_ the channel estimation makes the CIR peak move back to 0.
We have to take this into account on gNB side when calculating the timing advance command, and on UE side in the time adjustment.
This commit is contained in:
Thomas Schlichter
2021-04-26 14:58:01 +02:00
parent 626ab8aa3a
commit 942037beb3
2 changed files with 65 additions and 68 deletions
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openair1/PHY/NR_ESTIMATION/nr_measurements_gNB.c
+8 -9
View File
@@ -39,20 +39,20 @@ extern openair0_config_t openair0_cfg[MAX_CARDS];
int nr_est_timing_advance_pusch(PHY_VARS_gNB* gNB, int UE_id)
{
int i, aa, max_pos = 0, max_val = 0;
int 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->nb_prefix_samples / frame_parms->ofdm_offset_divisor;
for (i = 0; i < frame_parms->ofdm_symbol_size; i++) {
const int sync_pos = 0;
for (int i = 0; i < frame_parms->ofdm_symbol_size; i++) {
int temp = 0;
for (aa = 0; aa < frame_parms->nb_antennas_rx; aa++) {
short Re = ((int16_t*)ul_ch_estimates_time[aa])[(i<<1)];
short Im = ((int16_t*)ul_ch_estimates_time[aa])[1+(i<<1)];
for (int aa = 0; aa < frame_parms->nb_antennas_rx; aa++) {
int Re = ((int16_t*)ul_ch_estimates_time[aa])[(i<<1)];
int Im = ((int16_t*)ul_ch_estimates_time[aa])[1+(i<<1)];
temp += (Re*Re/2) + (Im*Im/2);
}
@@ -65,7 +65,6 @@ int nr_est_timing_advance_pusch(PHY_VARS_gNB* gNB, int UE_id)
if (max_pos > frame_parms->ofdm_symbol_size/2)
max_pos = max_pos - frame_parms->ofdm_symbol_size;
return max_pos - sync_pos;
}
openair1/PHY/NR_UE_ESTIMATION/nr_adjust_synch_ue.c
+57 -59
View File
@@ -45,25 +45,23 @@ void nr_adjust_synch_ue(NR_DL_FRAME_PARMS *frame_parms,
static int max_pos_fil = 0;
static int count_max_pos_ok = 0;
static int first_time = 1;
int temp = 0, i, aa, max_val = 0, max_pos = 0;
int diff;
short Re,Im,ncoef;
int max_val = 0, max_pos = 0;
const int sync_pos = 0;
uint8_t sync_offset = 0;
VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_UE_ADJUST_SYNCH, VCD_FUNCTION_IN);
ncoef = 32767 - coef;
short ncoef = 32767 - coef;
LOG_D(PHY,"AbsSubframe %d: rx_offset (before) = %d\n",subframe,ue->rx_offset);
// we only use channel estimates from tx antenna 0 here
for (i = 0; i < frame_parms->nb_prefix_samples; i++) {
temp = 0;
for (int i = 0; i < frame_parms->nb_prefix_samples; i++) {
int temp = 0;
for (aa=0; aa<frame_parms->nb_antennas_rx; aa++) {
Re = ((int16_t*)ue->pbch_vars[gNB_id]->dl_ch_estimates_time[aa])[(i<<1)];
Im = ((int16_t*)ue->pbch_vars[gNB_id]->dl_ch_estimates_time[aa])[1+(i<<1)];
for (int aa = 0; aa < frame_parms->nb_antennas_rx; aa++) {
int Re = ((int16_t*)ue->pbch_vars[gNB_id]->dl_ch_estimates_time[aa])[(i<<1)];
int Im = ((int16_t*)ue->pbch_vars[gNB_id]->dl_ch_estimates_time[aa])[1+(i<<1)];
temp += (Re*Re/2) + (Im*Im/2);
}
@@ -73,6 +71,9 @@ void nr_adjust_synch_ue(NR_DL_FRAME_PARMS *frame_parms,
}
}
if (max_pos > frame_parms->ofdm_symbol_size/2)
max_pos = max_pos - frame_parms->ofdm_symbol_size;
// filter position to reduce jitter
if (clear == 1)
max_pos_fil = max_pos;
@@ -82,61 +83,58 @@ void nr_adjust_synch_ue(NR_DL_FRAME_PARMS *frame_parms,
// do not filter to have proactive timing adjustment
//max_pos_fil = max_pos;
diff = max_pos_fil - (frame_parms->nb_prefix_samples / frame_parms->ofdm_offset_divisor);
int diff = max_pos_fil - sync_pos;
if (frame_parms->freq_range==nr_FR2)
sync_offset = 2;
else
sync_offset = 0;
if ( abs(diff) < (SYNCH_HYST+sync_offset) )
ue->rx_offset = 0;
else
ue->rx_offset = diff;
if (frame_parms->freq_range==nr_FR2)
sync_offset = 2;
else
sync_offset = 0;
if(abs(diff)<5)
count_max_pos_ok ++;
else
count_max_pos_ok = 0;
//printf("adjust sync count_max_pos_ok = %d\n",count_max_pos_ok);
if ( abs(diff) < (SYNCH_HYST+sync_offset) )
ue->rx_offset = 0;
else
ue->rx_offset = diff;
if(count_max_pos_ok > 10 && first_time == 1)
{
first_time = 0;
ue->time_sync_cell = 1;
if (get_softmodem_params()->do_ra) {
LOG_I(PHY,"[UE%d] Sending synch status to higher layers\n",ue->Mod_id);
//mac_resynch();
//dl_phy_sync_success(ue->Mod_id,frame,0,1);//ue->common_vars.eNb_id);
ue->UE_mode[0] = PRACH;
ue->prach_resources[gNB_id]->sync_frame = frame;
ue->prach_resources[gNB_id]->init_msg1 = 0;
} else {
ue->UE_mode[0] = PUSCH;
}
}
if(abs(diff)<5)
count_max_pos_ok ++;
else
count_max_pos_ok = 0;
//printf("adjust sync count_max_pos_ok = %d\n",count_max_pos_ok);
if (ue->rx_offset < 0)
ue->rx_offset += frame_parms->samples_per_frame;
if(count_max_pos_ok > 10 && first_time == 1)
{
first_time = 0;
ue->time_sync_cell = 1;
if (get_softmodem_params()->do_ra) {
LOG_I(PHY,"[UE%d] Sending synch status to higher layers\n",ue->Mod_id);
//mac_resynch();
//dl_phy_sync_success(ue->Mod_id,frame,0,1);//ue->common_vars.eNb_id);
ue->UE_mode[0] = PRACH;
ue->prach_resources[gNB_id]->sync_frame = frame;
ue->prach_resources[gNB_id]->init_msg1 = 0;
} else {
ue->UE_mode[0] = PUSCH;
}
}
if (ue->rx_offset >= frame_parms->samples_per_frame)
ue->rx_offset -= frame_parms->samples_per_frame;
if (ue->rx_offset < 0)
ue->rx_offset += frame_parms->samples_per_frame;
if (ue->rx_offset >= frame_parms->samples_per_frame)
ue->rx_offset -= frame_parms->samples_per_frame;
#ifdef DEBUG_PHY
LOG_D(PHY,"AbsSubframe %d: diff = %i, rx_offset (final) = %i : clear = %d, max_pos = %d, max_pos_fil = %d, max_val = %d, sync_pos %d\n",
subframe,
diff,
ue->rx_offset,
clear,
max_pos,
max_pos_fil,
max_val,
sync_pos);
#endif //DEBUG_PHY
#ifdef DEBUG_PHY
LOG_D(PHY,"AbsSubframe %d: diff =%i rx_offset (final) = %i : clear %d,max_pos = %d,max_pos_fil = %d (peak %d) max_val %d target_pos %d \n",
subframe,
diff,
ue->rx_offset,
clear,
max_pos,
max_pos_fil,
temp,max_val,
(frame_parms->nb_prefix_samples>>3));
#endif //DEBUG_PHY
VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_UE_ADJUST_SYNCH, VCD_FUNCTION_OUT);
VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_UE_ADJUST_SYNCH, VCD_FUNCTION_OUT);
}