Merge remote-tracking branch 'origin/nr_timing_fixes' into integration_2021_wk45_b

executables/nr-ue.c

@@ -460,13 +460,18 @@ int computeSamplesShift(PHY_VARS_NR_UE *UE) {
   // compute TO compensation that should be applied for this frame
   if ( UE->rx_offset < UE->frame_parms.samples_per_frame/2  &&
        UE->rx_offset > 0 ) {
-    //LOG_I(PHY,"!!!adjusting -1 samples!!!\n");
+    LOG_I(PHY,"!!!adjusting -1 samples!!! rx_offset == %d\n", UE->rx_offset);
+    UE->rx_offset   = 0; // reset so that it is not applied falsely in case of SSB being only in every second frame
+    UE->max_pos_fil = 0; // reset IIR filter when sample shift is applied
     return -1 ;
   }
 
   if ( UE->rx_offset > UE->frame_parms.samples_per_frame/2 &&
        UE->rx_offset < UE->frame_parms.samples_per_frame ) {
-    //LOG_I(PHY,"!!!adjusting +1 samples!!!\n");
+    int rx_offset = UE->rx_offset - UE->frame_parms.samples_per_frame;
+    LOG_I(PHY,"!!!adjusting +1 samples!!! rx_offset == %d\n", rx_offset);
+    UE->rx_offset   = 0; // reset so that it is not applied falsely in case of SSB being only in every second frame
+    UE->max_pos_fil = 0; // reset IIR filter when sample shift is applied
     return 1;
   }
 

openair1/PHY/NR_UE_ESTIMATION/nr_adjust_synch_ue.c

@@ -42,7 +42,6 @@ void nr_adjust_synch_ue(NR_DL_FRAME_PARMS *frame_parms,
                         short coef)
 {
 
-  static int max_pos_fil = 0;
   static int count_max_pos_ok = 0;
   static int first_time = 1;
   int max_val = 0, max_pos = 0;
@@ -55,13 +54,14 @@ void nr_adjust_synch_ue(NR_DL_FRAME_PARMS *frame_parms,
 
   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 (int i = 0; i < frame_parms->nb_prefix_samples; i++) {
+  // search for maximum position within the cyclic prefix
+  for (int i = -frame_parms->nb_prefix_samples/2; i < frame_parms->nb_prefix_samples/2; i++) {
     int temp = 0;
 
+    int j = (i < 0) ? (i + frame_parms->ofdm_symbol_size) : i;
     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)];
+      int Re = ((int16_t*)ue->pbch_vars[gNB_id]->dl_ch_estimates_time[aa])[(j<<1)];
+      int Im = ((int16_t*)ue->pbch_vars[gNB_id]->dl_ch_estimates_time[aa])[1+(j<<1)];
       temp += (Re*Re/2) + (Im*Im/2);
     }
 
@@ -71,19 +71,16 @@ 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;
+    ue->max_pos_fil = max_pos;
   else
-    max_pos_fil = ((max_pos_fil * coef) + (max_pos * ncoef)) >> 15;
+    ue->max_pos_fil = ((ue->max_pos_fil * coef) + (max_pos * ncoef)) >> 15;
 
   // do not filter to have proactive timing adjustment
-  //max_pos_fil = max_pos;
+  //ue->max_pos_fil = max_pos;
 
-  int diff = max_pos_fil - sync_pos;
+  int diff = ue->max_pos_fil - sync_pos;
 
   if (frame_parms->freq_range==nr_FR2) 
     sync_offset = 2;
@@ -131,7 +128,7 @@ void nr_adjust_synch_ue(NR_DL_FRAME_PARMS *frame_parms,
         ue->rx_offset,
         clear,
         max_pos,
-        max_pos_fil,
+        ue->max_pos_fil,
         max_val,
         sync_pos);
 #endif //DEBUG_PHY

openair1/PHY/defs_nr_UE.h

@@ -917,9 +917,10 @@ typedef struct {
   uint8_t               init_sync_frame;
   /// temporary offset during cell search prior to MIB decoding
   int              ssb_offset;
-  uint16_t	   symbol_offset; // offset in terms of symbols for detected ssb in sync
+  uint16_t         symbol_offset;  /// offset in terms of symbols for detected ssb in sync
   int              rx_offset;      /// Timing offset
   int              rx_offset_diff; /// Timing adjustment for ofdm symbol0 on HW USRP
+  int              max_pos_fil;    /// Timing offset IIR filter
   int              time_sync_cell;
 
   /// Timing Advance updates variables

openair1/SCHED_NR/phy_procedures_nr_gNB.c

@@ -403,8 +403,6 @@ void nr_fill_indication(PHY_VARS_gNB *gNB, int frame, int slot_rx, int ULSCH_id,
 
   pthread_mutex_lock(&gNB->UL_INFO_mutex);
 
-  int timing_advance_update, cqi;
-  int sync_pos;
   NR_gNB_ULSCH_t                       *ulsch                 = gNB->ulsch[ULSCH_id][0];
   NR_UL_gNB_HARQ_t                     *harq_process          = ulsch->harq_processes[harq_pid];
   NR_gNB_SCH_STATS_t *stats=get_ulsch_stats(gNB,ulsch);
@@ -412,19 +410,20 @@ void nr_fill_indication(PHY_VARS_gNB *gNB, int frame, int slot_rx, int ULSCH_id,
   nfapi_nr_pusch_pdu_t *pusch_pdu = &harq_process->ulsch_pdu;
 
   //  pdu->data                              = gNB->ulsch[ULSCH_id+1][0]->harq_processes[harq_pid]->b;
-  sync_pos                               = nr_est_timing_advance_pusch(gNB, ULSCH_id); // estimate timing advance for MAC
+  int sync_pos = nr_est_timing_advance_pusch(gNB, ULSCH_id); // estimate timing advance for MAC
 
   // scale the 16 factor in N_TA calculation in 38.213 section 4.2 according to the used FFT size
   uint16_t bw_scaling = 16 * gNB->frame_parms.ofdm_symbol_size / 2048;
-  int sync_pos_rounded;
+
   // do some integer rounding to improve TA accuracy
+  int sync_pos_rounded;
   if (sync_pos > 0)
     sync_pos_rounded = sync_pos + (bw_scaling / 2) - 1;
   else
-    sync_pos_rounded = sync_pos - (bw_scaling / 2) - 1;
+    sync_pos_rounded = sync_pos - (bw_scaling / 2) + 1;
   if (stats) stats->sync_pos = sync_pos;
 
-  timing_advance_update = sync_pos_rounded / bw_scaling;
+  int timing_advance_update = sync_pos_rounded / bw_scaling;
 
   // put timing advance command in 0..63 range
   timing_advance_update += 31;
@@ -449,6 +448,7 @@ void nr_fill_indication(PHY_VARS_gNB *gNB, int frame, int slot_rx, int ULSCH_id,
 
   LOG_D(PHY, "Estimated SNR for PUSCH is = %f dB (ulsch_power %f, noise %f)\n", SNRtimes10/10.0,dB_fixed_x10(gNB->pusch_vars[ULSCH_id]->ulsch_power_tot)/10.0,dB_fixed_x10(gNB->pusch_vars[ULSCH_id]->ulsch_noise_power_tot)/10.0);
 
+  int cqi;
   if      (SNRtimes10 < -640) cqi=0;
   else if (SNRtimes10 >  635) cqi=255;
   else                        cqi=(640+SNRtimes10)/5;