Initial NR PRS UE Channel estimation changes integrated to NR_PBCHSim

openair1/PHY/INIT/nr_init_ue.c

@@ -194,6 +194,22 @@ int init_nr_ue_signal(PHY_VARS_NR_UE *ue,
   ///////////
   ////////////////////////////////////////////////////////////////////////////////////////////
 
+  //PRS init
+  ue->nr_gold_prs = (uint32_t ***)malloc16(fp->slots_per_frame*sizeof(uint32_t **));
+  uint32_t ***prs = ue->nr_gold_prs;
+  AssertFatal(prs!=NULL, "NR UE init: positioning reference signal malloc failed\n");
+
+  for (int slot=0; slot<fp->slots_per_frame; slot++) {
+    prs[slot] = (uint32_t **)malloc16(fp->symbols_per_slot*sizeof(uint32_t *));
+    AssertFatal(prs[slot]!=NULL, "NR UE init: positioning reference signal for slot %d - malloc failed\n", slot);
+
+    for (int symb=0; symb<fp->symbols_per_slot; symb++) {
+      prs[slot][symb] = (uint32_t *)malloc16(NR_MAX_PRS_INIT_LENGTH_DWORD*sizeof(uint32_t));
+      AssertFatal(prs[slot][symb]!=NULL, "NR UE init: positioning reference signal for slot %d symbol %d - malloc failed\n", slot, symb);
+    }
+  }
+  nr_gold_prs(ue);
+
   /////////////////////////PUSCH DMRS init/////////////////////////
   ///////////
   ue->nr_gold_pusch_dmrs = (uint32_t ****)malloc16(fp->slots_per_frame*sizeof(uint32_t ***));
@@ -319,6 +335,16 @@ int init_nr_ue_signal(PHY_VARS_NR_UE *ue,
     prach_vars[gNB_id] = (NR_UE_PRACH *)malloc16_clear(sizeof(NR_UE_PRACH));
     pbch_vars[gNB_id] = (NR_UE_PBCH *)malloc16_clear(sizeof(NR_UE_PBCH));
 
+    // PRS channel estimates
+    ue->prs_ch_estimates = (int32_t **)malloc16( fp->nb_antennas_rx*sizeof(int32_t *) );
+    AssertFatal(ue->prs_ch_estimates!=NULL, "NR UE init: PRS channel estimates malloc failed\n");
+
+    for (i=0; i<fp->nb_antennas_rx; i++) {
+      ue->prs_ch_estimates[i] = (int32_t *)malloc16(2*fp->ofdm_symbol_size*NR_MAX_NUM_PRS_SYMB);
+      AssertFatal(ue->prs_ch_estimates[i]!=NULL, "NR UE init: PRS channel estimates malloc failed %d\n", i);
+    }
+
+
     if (abstraction_flag == 0) {
       for (th_id=0; th_id<RX_NB_TH_MAX; th_id++) {
         phy_init_nr_ue__PDSCH( ue->pdsch_vars[th_id][gNB_id], fp );

openair1/PHY/NR_REFSIG/nr_gold_ue.c

@@ -133,3 +133,39 @@ void nr_init_pusch_dmrs(PHY_VARS_NR_UE* ue,
     }
   }
 }
+
+void nr_gold_prs(PHY_VARS_NR_UE* ue)
+{
+  unsigned int x1, x2;
+  uint16_t Nid;
+
+  fapi_nr_config_request_t *cfg = &ue->nrUE_config;
+  NR_DL_FRAME_PARMS *fp = &ue->frame_parms;
+  uint8_t reset;
+  uint8_t slotNum, symNum;
+
+  Nid = cfg->cell_config.phy_cell_id;
+
+  for (slotNum = 0; slotNum < fp->slots_per_frame; slotNum++) {
+    for (symNum = 0; symNum < fp->symbols_per_slot ; symNum++) {
+      reset = 1;
+      // initial x2 for prs as ts138.211
+      uint32_t c_init1, c_init2, c_init3;
+      uint32_t pow22=1<<22;
+      uint32_t pow10=1<<10;
+      c_init1 = pow22*ceil(Nid/1024);
+      c_init2 = pow10*(slotNum+symNum+1)*(2*(Nid%1024)+1);
+      c_init3 = Nid%1024;
+      x2 = c_init1 + c_init2 + c_init3;
+      
+
+      for (uint8_t n=0; n<NR_MAX_PRS_INIT_LENGTH_DWORD; n++) {
+        ue->nr_gold_prs[slotNum][symNum][n] = lte_gold_generic(&x1, &x2, reset);      
+        reset = 0;
+        //printf("%d \n",gNB->nr_gold_prs[slotNum][symNum][n]); 
+	
+      }
+    }
+  }
+
+}

openair1/PHY/NR_REFSIG/refsig_defs_ue.h

@@ -67,4 +67,6 @@ void nr_init_pusch_dmrs(PHY_VARS_NR_UE* ue,
                         uint16_t *N_n_scid,
                         uint8_t n_scid);
 
+void nr_gold_prs(PHY_VARS_NR_UE* ue);
+
 #endif

openair1/PHY/NR_TRANSPORT/nr_prs.c

@@ -4,7 +4,7 @@
 #include "PHY/NR_REFSIG/nr_refsig.h"
 #include "PHY/sse_intrin.h"
 
-//#define DEBUG_PRS_MOD
+#define DEBUG_PRS_MOD
 #define DEBUG_PRS_MAP
 
 extern short nr_qpsk_mod_table[8];
@@ -65,7 +65,7 @@ printf("m %d idx %d gold seq %d mod_prs %d %d\n", m, idx, nr_gold_prs[l][(m<<1)>
 #endif
       
 #ifdef DEBUG_PRS_MAP
-printf("m %d at k %d of l %d\n", m, k, l);
+printf("m %d at k %d of l %d reIdx %d\n", m, k, l, (l*frame_parms->ofdm_symbol_size + k)<<1);
 #endif
       
       ((int16_t *)txdataF)[(l*frame_parms->ofdm_symbol_size + k)<<1]       = (amp * mod_prs[m<<1]) >> 15;

openair1/PHY/NR_UE_ESTIMATION/nr_dl_channel_estimation.c

@@ -28,11 +28,154 @@
 #include "PHY/NR_REFSIG/dmrs_nr.h"
 #include "PHY/NR_REFSIG/ptrs_nr.h"
 #include "PHY/NR_TRANSPORT/nr_sch_dmrs.h"
+#include "PHY/NR_TRANSPORT/nr_transport_proto.h"
 #include "filt16a_32.h"
 
 //#define DEBUG_PDSCH
 //#define DEBUG_PDCCH
+//#define DEBUG_CH
+#define DEBUG_PRS_CHEST
+extern short nr_qpsk_mod_table[8];
 
+int nr_prs_channel_estimation(PHY_VARS_NR_UE *ue,
+                              UE_nr_rxtx_proc_t *proc,
+                              NR_DL_FRAME_PARMS *frame_params)
+{
+  // Get K_Prime from the table for the length of PRS or LPRS
+  int k_prime_table[4][12] = {
+        {0,1,0,1,0,1,0,1,0,1,0,1},
+        {0,2,1,3,0,2,1,3,0,2,1,3},
+        {0,3,1,4,2,5,0,3,1,4,2,5},
+        {0,6,3,9,1,7,4,10,2,8,5,11}};
+    
+  int32_t **rxdataF      = ue->common_vars.common_vars_rx_data_per_thread[proc->thread_id].rxdataF;
+  uint32_t **nr_gold_prs = ue->nr_gold_prs[proc->nr_slot_rx];
+  prs_data_t *prs_cfg    = &ue->prs_cfg;
+  
+  int16_t *prs_chest, ch[2] = {0}, *rxF, *pil, *fl,*fm,*fr, mod_prs[NR_MAX_PRS_LENGTH<<1];
+  int16_t k_prime = 0, k = 0;
+  uint8_t idx = prs_cfg->NPRSID;
+  uint8_t rxAnt = 0; // ant 0 rxdataF for now
+
+  printf("Inside nr_prs_channel_estimation proc->thread_id %d, proc->nr_slot_rx %d\n", proc->thread_id, proc->nr_slot_rx);
+  for(int l = prs_cfg->SymbolStart; l < prs_cfg->SymbolStart+prs_cfg->NumPRSSymbols; l++)
+  {
+    int symInd = l-prs_cfg->SymbolStart;
+    if (prs_cfg->CombSize == 2) {
+      k_prime = k_prime_table[0][symInd];
+    }
+    else if (prs_cfg->CombSize == 4){
+      k_prime = k_prime_table[1][symInd];
+    }
+    else if (prs_cfg->CombSize == 6){
+      k_prime = k_prime_table[2][symInd];
+    }
+    else if (prs_cfg->CombSize == 12){
+      k_prime = k_prime_table[3][symInd];
+    }
+   
+  printf("PRS config l %d k_prime %d:\nprs_cfg->SymbolStart %d\nprs_cfg->NumPRSSymbols %d\nprs_cfg->NumRB %d\nprs_cfg->CombSize %d\n", l, k_prime, prs_cfg->SymbolStart, prs_cfg->NumPRSSymbols, prs_cfg->NumRB, prs_cfg->CombSize);
+    //TODO currently supported only comb_size 2 and 4
+    switch (k_prime) {
+      case 0:
+        fl = filt16a_l0;
+        fm = filt16a_m0;
+        fr = filt16a_r0;
+        break;
+      
+      case 1:
+        fl = filt16a_l1;
+        fm = filt16a_m1;
+        fr = filt16a_r1;
+        break;
+
+      case 2:
+        fl = filt16a_l2;
+        fm = filt16a_m2;
+        fr = filt16a_r2;
+        break;
+
+      case 3:
+        fl = filt16a_l3;
+        fm = filt16a_m3;
+        fr = filt16a_r3;
+        break;
+
+      default:
+        printf("nr=prs channel_estimation: k_prime=%d -> ERROR\n",k_prime);
+        return(-1);
+        break;
+    }
+    
+    //re_offset
+    k = (prs_cfg->REOffset+k_prime) % prs_cfg->CombSize + frame_params->first_carrier_offset;
+   
+    // Pilots generation and modulation
+    for (int m = 0; m < (12/prs_cfg->CombSize)*prs_cfg->NumRB; m++) 
+    {
+      idx = (((nr_gold_prs[l][(m<<1)>>5])>>((m<<1)&0x1f))&3);
+      mod_prs[m<<1]     = nr_qpsk_mod_table[idx<<1];
+      mod_prs[(m<<1)+1] = nr_qpsk_mod_table[(idx<<1) + 1];
+    } 
+
+    pil       = (int16_t *)&mod_prs[0];
+    rxF       = (int16_t *)&rxdataF[rxAnt][l*frame_params->ofdm_symbol_size + k];
+    prs_chest = (int16_t *)&ue->prs_ch_estimates[rxAnt][l*frame_params->ofdm_symbol_size];
+    memset(prs_chest,0,4*(ue->frame_parms.ofdm_symbol_size));
+    for(int pIdx = 0; pIdx < prs_cfg->NumRB*(12/prs_cfg->CombSize); pIdx+=3) 
+    {
+      //pilot 0
+      ch[0] = (int16_t)(((int32_t)rxF[0]*pil[0] + (int32_t)rxF[1]*pil[1])>>15);
+      ch[1] = (int16_t)(((int32_t)rxF[1]*pil[0] - (int32_t)rxF[0]*pil[1])>>15);
+      
+#ifdef DEBUG_PRS_CHEST
+      printf("pilIdx %d at k %d of l %d reIdx %d rxF %d %d ch[0] %d ch[1] %d\n", pIdx, k, l, (l*frame_params->ofdm_symbol_size + k), rxF[0], rxF[1], ch[0], ch[1]);
+#endif
+      
+      multadd_real_vector_complex_scalar(fl,
+				       ch,
+				       prs_chest,
+				       16);
+      
+      pil +=2;
+      k   = (k+prs_cfg->CombSize) % frame_params->ofdm_symbol_size;
+      rxF = (int16_t *)&rxdataF[rxAnt][l*frame_params->ofdm_symbol_size + k];
+      
+      //pilot 1
+      ch[0] = (int16_t)(((int32_t)rxF[0]*pil[0] + (int32_t)rxF[1]*pil[1])>>15);
+      ch[1] = (int16_t)(((int32_t)rxF[1]*pil[0] - (int32_t)rxF[0]*pil[1])>>15);
+      
+      multadd_real_vector_complex_scalar(fm,
+				       ch,
+				       prs_chest,
+				       16);
+      
+      pil +=2;
+      k   = (k+prs_cfg->CombSize) % frame_params->ofdm_symbol_size;
+      rxF = (int16_t *)&rxdataF[rxAnt][l*frame_params->ofdm_symbol_size + k];
+      
+      //pilot 2
+      ch[0] = (int16_t)(((int32_t)rxF[0]*pil[0] + (int32_t)rxF[1]*pil[1])>>15);
+      ch[1] = (int16_t)(((int32_t)rxF[1]*pil[0] - (int32_t)rxF[0]*pil[1])>>15);
+      
+      multadd_real_vector_complex_scalar(fr,
+				       ch,
+				       prs_chest,
+				       16);
+      
+      pil +=2;
+      k   = (k+prs_cfg->CombSize) % frame_params->ofdm_symbol_size;
+      rxF = (int16_t *)&rxdataF[rxAnt][l*frame_params->ofdm_symbol_size + k];
+      for (int re = 0; re < 12; re++)
+        printf("prs_ch[%d] %d %d\n", re, prs_chest[re<<1], prs_chest[(re<<1)+1]);
+      
+      prs_chest +=24; 
+    } //for m
+  } //for l
+  
+  LOG_M("prsEst.m","prs_chest",&ue->prs_ch_estimates[rxAnt][prs_cfg->SymbolStart*frame_params->ofdm_symbol_size], prs_cfg->NumRB*12,1,1 );
+  return(0);
+}
 
 int nr_pbch_dmrs_correlation(PHY_VARS_NR_UE *ue,
                              UE_nr_rxtx_proc_t *proc,
@@ -395,6 +538,10 @@ int nr_pbch_channel_estimation(PHY_VARS_NR_UE *ue,
 					 ch,
 					 dl_ch,
 					 16);
+#ifdef DEBUG_CH
+      for (int re = 0; re < 12; re++)
+        printf("dl_ch[%d] %d %d\n", re, dl_ch[re<<1], dl_ch[(re<<1)+1]);
+#endif
       pil += 2;
       re_offset = (re_offset+4) % ue->frame_parms.ofdm_symbol_size;
       rxF   = (int16_t *)&rxdataF[aarx][(symbol_offset+k+re_offset)];
@@ -485,8 +632,8 @@ int nr_pdcch_channel_estimation(PHY_VARS_NR_UE *ue,
 
 
 #ifdef DEBUG_PDCCH
-  printf("PDCCH Channel Estimation : ThreadId %d, gNB_id %d ch_offset %d, OFDM size %d, Ncp=%d, Ns=%d, k=%d symbol %d\n",proc->thread_id, gNB_id,ch_offset,ue->frame_parms.ofdm_symbol_size,
+  printf("PDCCH Channel Estimation : ThreadId %d, gNB_id %d ch_offset %d, OFDM size %d, Ncp=%d, Ns=%d, symbol %d\n",
-         ue->frame_parms.Ncp,Ns,k, symbol);
+         proc->thread_id, gNB_id,ch_offset,ue->frame_parms.ofdm_symbol_size,ue->frame_parms.Ncp,Ns,symbol);
 #endif
 
   fl = filt16a_l1;

openair1/PHY/NR_UE_ESTIMATION/nr_estimation.h

@@ -32,6 +32,11 @@
 /*!\brief Timing drift hysterisis in samples*/
 #define SYNCH_HYST 2
 
+/* A function to perform the channel estimation of DL PRS signal */
+int nr_prs_channel_estimation(PHY_VARS_NR_UE *ue,
+                              UE_nr_rxtx_proc_t *proc,
+                              NR_DL_FRAME_PARMS *frame_params);
+
 /*!
 \brief This function performs channel estimation including frequency and temporal interpolation
 \param ue Pointer to UE PHY variables

openair1/PHY/defs_gNB.h

@@ -48,6 +48,7 @@
 #define MAX_NUM_RU_PER_gNB MAX_NUM_RU_PER_eNB
 #define MAX_PUCCH0_NID 8
 
+
 typedef struct {
   int nb_id;
   int Nid[MAX_PUCCH0_NID];
@@ -779,6 +780,7 @@ typedef struct PHY_VARS_gNB_s {
   NR_gNB_SCH_STATS_t ulsch_stats[NUMBER_OF_NR_SCH_STATS_MAX];
   NR_gNB_UCI_STATS_t uci_stats[NUMBER_OF_NR_UCI_STATS_MAX];
   t_nrPolar_params    *uci_polarParams;
+  prs_data_t prs_cfg;
 
   uint8_t pbch_configured;
   char gNB_generate_rar;
@@ -949,23 +951,6 @@ typedef struct processingData_L1 {
   PHY_VARS_gNB *gNB;
 } processingData_L1_t;
 
-// structures prototype
-typedef struct prs {
-    int PRSResourceSetPeriod[2]; //[slot period, slot offset]
-    int PRSResourceOffset; // array if more than one resource sets.slot offset (0...511) (default 0)
-    int PRSResourceRepetition;// slot offset (1 (default), 2, 4, 6, 8, 16, 32)
-    int PRSResourceTimeGap; // slot offset (1 (default), 2, 4, 6, 8, 16, 32)
-    int NumRB; //number of RBs in freq domain a scalar =< 275 RB
-    int NumPRSSymbols; //number of PRS symbols in time domain
-    int SymbolStart; //starting OFDM symbol of PRS resource in time domain
-    int RBOffset; //Starting PRB index of all PRS resources in a PRS resource set.
-    int CombSize; //RE density of all PRS resources in a PRS resource set. i∈{2,4,6,12}
-    int REOffset; //Starting RE offset in the first OFDM symbol of each PRS resource in a PRS resource set.
-    int MutingPattern1[2]; //Muting bit pattern option-1, specified as [] or a binary-valued vector of length 2, 4, 6, 8, 16, or 32.
-    int MutingPattern2[2];
-    int MutingBitRepetition;
-    int NPRSID;
-} prs_data_t;
 
 
 #endif

openair1/PHY/defs_nr_UE.h

@@ -823,7 +823,8 @@ typedef struct {
   NR_UE_DLSCH_t   *dlsch_ra[NUMBER_OF_CONNECTED_gNB_MAX];
   NR_UE_DLSCH_t   *dlsch_p[NUMBER_OF_CONNECTED_gNB_MAX];
   NR_UE_DLSCH_t   *dlsch_MCH[NUMBER_OF_CONNECTED_gNB_MAX];
-
+  prs_data_t prs_cfg;
+  
   //Paging parameters
   uint32_t              IMSImod1024;
   uint32_t              PF;
@@ -845,6 +846,7 @@ typedef struct {
 
 #endif
 
+  int32_t **prs_ch_estimates;
 
   /// PBCH DMRS sequence
   uint32_t nr_gold_pbch[2][64][NR_PBCH_DMRS_LENGTH_DWORD];
@@ -864,6 +866,9 @@ typedef struct {
   /// PUSCH DMRS sequence
   uint32_t ****nr_gold_pusch_dmrs;
 
+  // PRS sequence
+  uint32_t ***nr_gold_prs;
+  
   uint32_t X_u[64][839];
 
 

openair1/PHY/defs_nr_common.h

@@ -82,6 +82,7 @@
 
 #define NR_MAX_PRS_LENGTH 3264 //272*6(max allocation per RB)*2(QPSK)
 #define NR_MAX_PRS_INIT_LENGTH_DWORD 102 // ceil(NR_MAX_CSI_RS_LENGTH/32)
+#define NR_MAX_NUM_PRS_SYMB 12
 
 #define NR_MAX_PUSCH_DMRS_LENGTH NR_MAX_PDSCH_DMRS_LENGTH 
 #define NR_MAX_PUSCH_DMRS_INIT_LENGTH_DWORD NR_MAX_PDSCH_DMRS_INIT_LENGTH_DWORD
@@ -372,7 +373,23 @@ struct NR_DL_FRAME_PARMS {
   uint32_t ofdm_offset_divisor;
 };
 
-
+// PRS structures prototype
+typedef struct prs {
+    int PRSResourceSetPeriod[2]; //[slot period, slot offset]
+    int PRSResourceOffset; // array if more than one resource sets.slot offset (0...511) (default 0)
+    int PRSResourceRepetition;// slot offset (1 (default), 2, 4, 6, 8, 16, 32)
+    int PRSResourceTimeGap; // slot offset (1 (default), 2, 4, 6, 8, 16, 32)
+    int NumRB; //number of RBs in freq domain a scalar =< 275 RB
+    int NumPRSSymbols; //number of PRS symbols in time domain
+    int SymbolStart; //starting OFDM symbol of PRS resource in time domain
+    int RBOffset; //Starting PRB index of all PRS resources in a PRS resource set.
+    int CombSize; //RE density of all PRS resources in a PRS resource set. i∈{2,4,6,12}
+    int REOffset; //Starting RE offset in the first OFDM symbol of each PRS resource in a PRS resource set.
+    int MutingPattern1[2]; //Muting bit pattern option-1, specified as [] or a binary-valued vector of length 2, 4, 6, 8, 16, or 32.
+    int MutingPattern2[2];
+    int MutingBitRepetition;
+    int NPRSID;
+} prs_data_t;
 
 #define KHz (1000UL)
 #define MHz (1000*KHz)

openair1/SCHED_NR/phy_procedures_nr_gNB.c

@@ -108,7 +108,7 @@ void nr_common_signal_procedures (PHY_VARS_gNB *gNB,int frame,int slot,nfapi_nr_
   prs_data.NumPRSSymbols=6;
   prs_data.NumRB=273;
   prs_data.RBOffset=0;
-  prs_data.CombSize=6;
+  prs_data.CombSize=4;
   prs_data.REOffset=0;
   prs_data.PRSResourceOffset=0;
   prs_data.PRSResourceRepetition=1;
@@ -239,7 +239,7 @@ void phy_procedures_gNB_TX(PHY_VARS_gNB *gNB,
   prs_data.NumPRSSymbols=6;
   prs_data.NumRB=273;
   prs_data.RBOffset=0;
-  prs_data.CombSize=6;
+  prs_data.CombSize=4;
   prs_data.REOffset=0;
   prs_data.PRSResourceOffset=0;
   prs_data.PRSResourceRepetition=1;

openair1/SCHED_NR_UE/phy_procedures_nr_ue.c

@@ -1716,6 +1716,8 @@ int phy_procedures_nrUE_RX(PHY_VARS_NR_UE *ue,
 #if UE_TIMING_TRACE
       stop_meas(&ue->dlsch_channel_estimation_stats);
 #endif
+      //PRS channel estimation
+      nr_prs_channel_estimation(ue,proc,fp);
     }
 
     nr_ue_rsrp_measurements(ue, gNB_id, proc, nr_slot_rx, 0);

openair1/SIMULATION/NR_PHY/pbchsim.c

@@ -722,16 +722,35 @@ int main(int argc, char **argv)
         while (!((SSB_positions >> ssb_index) & 0x01)) ssb_index++;  // to select the first transmitted ssb
 	UE->symbol_offset = nr_get_ssb_start_symbol(frame_parms,ssb_index);
 
-        int ssb_slot = (UE->symbol_offset/14)+(n_hf*(frame_parms->slots_per_frame>>1));
+  int ssb_slot = (UE->symbol_offset/14)+(n_hf*(frame_parms->slots_per_frame>>1));
-	for (int i=UE->symbol_offset+1; i<UE->symbol_offset+4; i++) {
+      
+  for(int j = 0; j < frame_parms->symbols_per_slot; j++)
+  {
           nr_slot_fep(UE,
                       &proc,
-                      i%frame_parms->symbols_per_slot,
+                      j%frame_parms->symbols_per_slot,
                       ssb_slot);
+  }
 
+	for (int i=UE->symbol_offset+1; i<UE->symbol_offset+4; i++) {
           nr_pbch_channel_estimation(UE,&proc,0,ssb_slot,i%frame_parms->symbols_per_slot,i-(UE->symbol_offset+1),ssb_index%8,n_hf);
+  }
 
-        }
+      UE->prs_cfg.PRSResourceSetPeriod[0]=40; // PRS resource slot period
+      UE->prs_cfg.PRSResourceSetPeriod[1]=0;  // resource slot offset
+      UE->prs_cfg.SymbolStart=7;		
+      UE->prs_cfg.NumPRSSymbols=6;
+      UE->prs_cfg.NumRB=273;
+      UE->prs_cfg.RBOffset=0;
+      UE->prs_cfg.CombSize=4;
+      UE->prs_cfg.REOffset=0;
+      UE->prs_cfg.PRSResourceOffset=0;
+      UE->prs_cfg.PRSResourceRepetition=1;
+      UE->prs_cfg.PRSResourceTimeGap=1;
+      UE->prs_cfg.NPRSID=0;
+
+      //PRS channel estimation
+      nr_prs_channel_estimation(UE,&proc,frame_parms);
 
         ret = nr_rx_pbch(UE,
                          &proc,