change timing advance to only affect the TX timestamp, not the position in the "txdata" buffer

executables/nr-ue.c

@@ -797,7 +797,7 @@ void *UE_thread(void *arg) {
                      timestamp+
                      UE->frame_parms.get_samples_slot_timestamp(slot_nr,
                      &UE->frame_parms,DURATION_RX_TO_TX - RX_NB_TH) - firstSymSamp -
-                     openair0_cfg[0].tx_sample_advance,
+                     openair0_cfg[0].tx_sample_advance - UE->N_TA_offset - UE->timing_advance,
                      txp,
                      writeBlockSize,
                      UE->frame_parms.nb_antennas_tx,

executables/nr-uesoftmodem.c

@@ -767,13 +767,7 @@ int main( int argc, char **argv ) {
   for(int CC_id=0; CC_id<MAX_NUM_CCs; CC_id++) {
     PHY_vars_UE_g[0][CC_id]->rf_map.card=0;
     PHY_vars_UE_g[0][CC_id]->rf_map.chain=CC_id+chain_offset;
-#if defined(OAI_USRP) || defined(OAI_ADRV9371_ZC706)
-    PHY_vars_UE_g[0][CC_id]->hw_timing_advance = timing_advance;
     PHY_vars_UE_g[0][CC_id]->timing_advance = timing_advance;
-#else
-    PHY_vars_UE_g[0][CC_id]->hw_timing_advance = 160;
-#endif
-
   }
 
   init_NR_UE_threads(1);

openair1/PHY/NR_UE_TRANSPORT/nr_prach.c

@@ -71,7 +71,7 @@ int32_t generate_nr_prach(PHY_VARS_NR_UE *ue, uint8_t gNB_id, uint8_t slot){
   int16_t prach_tmp[98304*2*4] __attribute__((aligned(32)));
 
   int16_t Ncp = 0, amp, *prach, *prach2, *prachF, *Xu;
-  int32_t Xu_re, Xu_im, samp_count;
+  int32_t Xu_re, Xu_im;
   int prach_start, prach_sequence_length, i, prach_len, dftlen, mu, kbar, K, n_ra_prb, k;
   //int restricted_Type;
 
@@ -103,22 +103,7 @@ int32_t generate_nr_prach(PHY_VARS_NR_UE *ue, uint8_t gNB_id, uint8_t slot){
                        nrUE_config->prach_config.num_prach_fd_occasions_list[fd_occasion].prach_root_sequence_index,
                        ue->X_u);
 
-  if (mu == 0)
-    samp_count = fp->samples_per_subframe;
-  else
-    samp_count = (slot%(fp->slots_per_subframe/2)) ? fp->samples_per_slotN0 : fp->samples_per_slot0;
-
-  #ifdef OAI_USRP
-    prach_start = (ue->rx_offset + slot*samp_count - ue->hw_timing_advance - ue->N_TA_offset);
-  #else //normal case (simulation)
-    prach_start = slot*samp_count - ue->N_TA_offset;
-  #endif
-
-  if (prach_start<0)
-    prach_start += (fp->samples_per_subframe*NR_NUMBER_OF_SUBFRAMES_PER_FRAME);
-
-  if (prach_start >= (fp->samples_per_subframe*NR_NUMBER_OF_SUBFRAMES_PER_FRAME))
-    prach_start -= (fp->samples_per_subframe*NR_NUMBER_OF_SUBFRAMES_PER_FRAME);
+  prach_start = fp->get_samples_slot_timestamp(slot, fp, 0);
 
   // First compute physical root sequence
   /************************************************************************
@@ -796,40 +781,16 @@ int32_t generate_nr_prach(PHY_VARS_NR_UE *ue, uint8_t gNB_id, uint8_t slot){
   }
 
   #ifdef NR_PRACH_DEBUG
-    LOG_I(PHY, "PRACH [UE %d] N_RB_UL %d prach_start %d, prach_len %d, rx_offset %d, hw_timing_advance %d, N_TA_offset %d\n", Mod_id,
+    LOG_I(PHY, "PRACH [UE %d] N_RB_UL %d prach_start %d, prach_len %d\n", Mod_id,
       fp->N_RB_UL,
       prach_start,
-      prach_len,
-      ue->rx_offset,
-      ue->hw_timing_advance,
-      ue->N_TA_offset);
+      prach_len);
   #endif
 
-  #if defined(OAI_USRP) || defined(OAI_BLADERF) || defined(OAI_LMSSDR)
-    int j, overflow = prach_start + prach_len - NR_NUMBER_OF_SUBFRAMES_PER_FRAME*fp->samples_per_subframe;
-
-    #ifdef NR_PRACH_DEBUG
-      LOG_I( PHY, "PRACH [UE %d] overflow = %d\n", Mod_id, overflow);
-    #endif
-
-    // prach_start=414.730, overflow=-39470 prach_len=6600 fp->samples_per_subframe*NR_NUMBER_OF_SUBFRAMES_PER_FRAME 460.800 prach_start+prach_len 421.330 fp->samples_per_subframe 46080
-
-    // from prach_start=414.730 to prach_start+prach_len 421.330
-    for (i = prach_start, j = 0; i < min(fp->samples_per_subframe*NR_NUMBER_OF_SUBFRAMES_PER_FRAME, prach_start + prach_len); i++, j++) {
-      ((int16_t*)ue->common_vars.txdata[0])[2*i] = prach[2*j];
-      ((int16_t*)ue->common_vars.txdata[0])[2*i+1] = prach[2*j+1];
-    }
-
-    for (i = 0; i < overflow; i++,j++) {
-      ((int16_t*)ue->common_vars.txdata[0])[2*i] = prach[2*j];
-      ((int16_t*)ue->common_vars.txdata[0])[2*i+1] = prach[2*j+1];
-    }
-  #else // simulators
   for (i=0; i<prach_len; i++) {
     ((int16_t*)(&ue->common_vars.txdata[0][prach_start]))[2*i] = prach[2*i];
     ((int16_t*)(&ue->common_vars.txdata[0][prach_start]))[2*i+1] = prach[2*i+1];
   }
-  #endif
 
   //printf("----------------------\n");
   //for(int ii = prach_start; ii<2*(prach_start + prach_len); ii++){

openair1/PHY/NR_UE_TRANSPORT/nr_ulsch_ue.c

@@ -434,22 +434,12 @@ uint8_t nr_ue_pusch_common_procedures(PHY_VARS_NR_UE *UE,
   int tx_offset, ap;
   int32_t **txdata;
   int32_t **txdataF;
-  int timing_advance;
   uint8_t Nl = UE->ulsch[thread_id][gNB_id][0]->harq_processes[harq_pid]->pusch_pdu.nrOfLayers; // cw 0
 
   /////////////////////////IFFT///////////////////////
   ///////////
 
-#if defined(EXMIMO) || defined(OAI_USRP) || defined(OAI_BLADERF) || defined(OAI_LMSSDR)  || defined(OAI_ADRV9371_ZC706)
-  timing_advance = UE->timing_advance;
-#else
-  timing_advance = 0;
-#endif
-
-  tx_offset = frame_parms->get_samples_slot_timestamp(slot,frame_parms,0) - timing_advance;
-
-  if (tx_offset < 0)
-    tx_offset += frame_parms->samples_per_frame;
+  tx_offset = frame_parms->get_samples_slot_timestamp(slot, frame_parms, 0);
 
   // clear the transmit data array for the current subframe
   /*for (int aa=0; aa<UE->frame_parms.nb_antennas_tx; aa++) {
@@ -461,51 +451,21 @@ uint8_t nr_ue_pusch_common_procedures(PHY_VARS_NR_UE *UE,
   txdata = UE->common_vars.txdata;
   txdataF = UE->common_vars.txdataF;
 
-  if(UE->N_TA_offset > tx_offset) {
-    int32_t *tmp_idft_out = (int32_t*)malloc16(frame_parms->get_samples_per_slot(slot, frame_parms) * sizeof(int32_t));
-
-    for(ap = 0; ap < Nl; ap++) {
-      if (frame_parms->Ncp == 1) { // extended cyclic prefix
-        PHY_ofdm_mod(txdataF[ap],
-                     tmp_idft_out,
-                     frame_parms->ofdm_symbol_size,
-                     12,
-                     frame_parms->nb_prefix_samples,
-                     CYCLIC_PREFIX);
-      } else { // normal cyclic prefix
-        nr_normal_prefix_mod(txdataF[ap],
-                             tmp_idft_out,
-                             14,
-                             frame_parms);
-      }
-
-      memcpy((void *) &txdata[ap][frame_parms->samples_per_frame - UE->N_TA_offset + tx_offset],
-             (void *) tmp_idft_out,
-             (UE->N_TA_offset - tx_offset) * sizeof(int32_t));
-
-      memcpy((void *) &txdata[ap][0],
-             (void *) &tmp_idft_out[UE->N_TA_offset - tx_offset],
-             (frame_parms->get_samples_per_slot(slot, frame_parms) - UE->N_TA_offset + tx_offset) * sizeof(int32_t));
-    }
-
-    free(tmp_idft_out);
-  } else { // UE->N_TA_offset <= tx_offset
   for (ap = 0; ap < Nl; ap++) {
     if (frame_parms->Ncp == 1) { // extended cyclic prefix
       PHY_ofdm_mod(txdataF[ap],
-                     &txdata[ap][tx_offset-UE->N_TA_offset],
+                   &txdata[ap][tx_offset],
                    frame_parms->ofdm_symbol_size,
                    12,
                    frame_parms->nb_prefix_samples,
                    CYCLIC_PREFIX);
     } else { // normal cyclic prefix
       nr_normal_prefix_mod(txdataF[ap],
-                             &txdata[ap][tx_offset-UE->N_TA_offset],
+                           &txdata[ap][tx_offset],
                            14,
                            frame_parms);
     }
   }
-  }
 
   ///////////
   ////////////////////////////////////////////////////

openair1/PHY/defs_nr_UE.h

@@ -1022,7 +1022,6 @@ typedef struct {
   /// Timing Advance updates variables
   /// Timing advance update computed from the TA command signalled from gNB
   int                      timing_advance;
-  int                      hw_timing_advance;
   int                      N_TA_offset; ///timing offset used in TDD
   NR_UL_TIME_ALIGNMENT_t   ul_time_alignment[NUMBER_OF_CONNECTED_gNB_MAX];
 

openair1/SIMULATION/NR_PHY/prachsim.c

@@ -603,7 +603,7 @@ int main(int argc, char **argv){
   /* tx_lev_dB not used later, no need to set */
   //tx_lev_dB = (unsigned int) dB_fixed(tx_lev);
 
-  prach_start = subframe*frame_parms->samples_per_subframe-UE->N_TA_offset;
+  prach_start = subframe*frame_parms->samples_per_subframe;
 
   #ifdef NR_PRACH_DEBUG
   LOG_M("txsig0.m", "txs0", &txdata[0][subframe*frame_parms->samples_per_subframe], frame_parms->samples_per_subframe, 1, 1);