diff --git a/openair1/PHY/NR_TRANSPORT/nr_prs.c b/openair1/PHY/NR_TRANSPORT/nr_prs.c
index 3e2cee2e7b..ce09751ae8 100644
--- a/openair1/PHY/NR_TRANSPORT/nr_prs.c
+++ b/openair1/PHY/NR_TRANSPORT/nr_prs.c
@@ -1,12 +1,11 @@
-
 #include "PHY/defs_gNB.h"
 #include "PHY/NR_TRANSPORT/nr_transport_proto.h"
 #include "PHY/LTE_REFSIG/lte_refsig.h"
 #include "PHY/NR_REFSIG/nr_refsig.h"
 #include "PHY/sse_intrin.h"
 
-//#define DEBUG_PRS
-#define DEBUG_PRS_MAP
+#define DEBUG_PRS_MOD
+//#define DEBUG_PRS_MAP
 
 extern short nr_qpsk_mod_table[8];
 
@@ -30,7 +29,6 @@ int nr_generate_prs(uint32_t **nr_gold_prs,
   int16_t mod_prs[NR_MAX_PRS_LENGTH<<1];
   uint8_t idx=prs_data->NPRSID;
   
-  // QPSK modulation
   
    // PRS resource mapping with combsize=k which means PRS symbols exist in every k-th subcarrier in frequency domain
    // According to ts138.211 sec.7.4.1.7.2
@@ -52,41 +50,37 @@ int nr_generate_prs(uint32_t **nr_gold_prs,
     }
     
     k = (prs_data->REOffset+k_prime) % prs_data->CombSize + frame_parms->ssb_start_subcarrier;
-    for (int m = 0; m < 12/prs_data->CombSize * prs_data->NumRB; m++) {
-      
-#ifdef DEBUG_PRS_MAP
-      printf("m %d at k %d of l %d\n", m, k, l);
-#endif
-
+    
+    // QPSK modulation
+    
+    for (int m = 0; m < (12/prs_data->CombSize) * prs_data->NumRB; m++) {
       idx = nr_gold_prs[l][m];
       mod_prs[m<<1] = nr_qpsk_mod_table[idx<<1];
       mod_prs[(m<<1)+1] = nr_qpsk_mod_table[(idx<<1) + 1];
+      
+      #ifdef DEBUG_PRS_MOD
+      printf("m %d idx %d gold seq %d mod_prs %d %d\n", m, idx, nr_gold_prs[l][m], mod_prs[(idx<<1)], mod_prs[(idx<<1)+1]);
+      #endif
+      
+      #ifdef DEBUG_PRS_MAP
+      printf("m %d at k %d of l %d\n", m, k, l);
+      #endif
+      
+      ((int16_t *)txdataF)[(l*frame_parms->ofdm_symbol_size + k)<<1]       = (amp * mod_prs[m<<1]) >> 15;
+      ((int16_t *)txdataF)[((l*frame_parms->ofdm_symbol_size + k)<<1) + 1] = (amp * mod_prs[(m<<1) + 1]) >> 15;
     
-#ifdef DEBUG_PRS
-    printf("m %d idx %d gold seq %d mod_prs %d %d\n", m, idx, nr_gold_prs[l][m], mod_prs[(idx<<1)], mod_prs[(idx<<1)+1]);
-#endif
-
-
-    ((int16_t *)txdataF)[(l*frame_parms->ofdm_symbol_size + k)<<1]       = (amp * mod_prs[m<<1]) >> 15;
-    ((int16_t *)txdataF)[((l*frame_parms->ofdm_symbol_size + k)<<1) + 1] = (amp * mod_prs[(m<<1) + 1]) >> 15;
-
-#ifdef DEBUG_PRS_MAP
-    printf("(%d,%d)\n",
+      #ifdef DEBUG_PRS_MAP
+      printf("(%d,%d)\n",
            ((int16_t *)txdataF)[(l*frame_parms->ofdm_symbol_size + k)<<1],
            ((int16_t *)txdataF)[((l*frame_parms->ofdm_symbol_size + k)<<1)+1]);
-#endif
+      #endif
 
-    k = k +  prs_data->CombSize;
+      k = k +  prs_data->CombSize;
     
-    if (k >= frame_parms->ofdm_symbol_size)
-      k-=frame_parms->ofdm_symbol_size;
-      
+      if (k >= frame_parms->ofdm_symbol_size)
+        k-=frame_parms->ofdm_symbol_size;
       }
   }
   
   return 0;
 }
- 
-
-
-
diff --git a/openair1/SCHED_NR/phy_procedures_nr_gNB.c b/openair1/SCHED_NR/phy_procedures_nr_gNB.c
index b771a9234d..e004c68e49 100644
--- a/openair1/SCHED_NR/phy_procedures_nr_gNB.c
+++ b/openair1/SCHED_NR/phy_procedures_nr_gNB.c
@@ -104,8 +104,19 @@ void nr_common_signal_procedures (PHY_VARS_gNB *gNB,int frame,int slot,nfapi_nr_
     nr_generate_pbch_dmrs(gNB->nr_gold_pbch_dmrs[0][ssb_index&7],&txdataF[0][txdataF_offset], AMP, ssb_start_symbol, cfg, fp);
     
   prs_data_t prs_data;
-  prs_data.PRSResourceSetPeriod[0]=0;
-  prs_data.PRSResourceSetPeriod[1]=0;
+  prs_data.PRSResourceSetPeriod[0]=40; // PRS resource slot period
+  prs_data.PRSResourceSetPeriod[1]=0;  // resource slot offset
+  prs_data.SymbolStart=5;		
+  prs_data.NumPRSSymbols=6;
+  prs_data.NumRB=106;
+  prs_data.RBOffset=0;
+  prs_data.CombSize=6;
+  prs_data.REOffset=0;
+  prs_data.PRSResourceOffset=0;
+  prs_data.PRSResourceRepetition=1;
+  prs_data.PRSResourceTimeGap=1;
+  prs_data.NPRSID=0;
+  printf(" before Combsize %d \n", prs_data.CombSize);
   // tbc
 
   nr_generate_prs(gNB->nr_gold_prs[slot],&txdataF[0][txdataF_offset], AMP, &prs_data, cfg, fp);
@@ -238,10 +249,12 @@ void phy_procedures_gNB_TX(PHY_VARS_gNB *gNB,
   prs_data.PRSResourceRepetition=1;
   prs_data.PRSResourceTimeGap=1;
   prs_data.NPRSID=0;
+  printf(" before %p \n",&prs_data);
   
   // tbc
   
   nr_generate_prs(gNB->nr_gold_prs[slot],&txdataF[0][txdataF_offset], AMP, &prs_data, cfg, fp);
+  
 
   if (do_meas==1) stop_meas(&gNB->phy_proc_tx);