Adding PTRS symbol from gNB in DL

- Based upon ptrs bitmap, ptrs symbols are added in DL
- Mac ptrs validation condition is updated

openair1/PHY/NR_TRANSPORT/nr_dlsch.c

@@ -35,6 +35,7 @@
 #include "nr_sch_dmrs.h"
 #include "PHY/MODULATION/nr_modulation.h"
 #include "PHY/NR_REFSIG/dmrs_nr.h"
+#include "PHY/NR_REFSIG/ptrs_nr.h"
 #include "common/utils/LOG/vcd_signal_dumper.h"
 
 //#define DEBUG_DLSCH
@@ -163,6 +164,23 @@ uint8_t nr_generate_pdsch(PHY_VARS_gNB *gNB,
     uint32_t encoded_length = nb_re*Qm;
     int16_t mod_dmrs[n_dmrs<<1] __attribute__ ((aligned(16)));
 
+    /* PTRS */
+    uint16_t beta_ptrs = 1;
+    uint8_t ptrs_symbol = 0;
+    uint16_t dlPtrsSymPos = 0;
+    uint16_t n_ptrs = 0;
+    uint16_t ptrs_idx = 0;
+    uint8_t is_ptrs_re = 0;
+    if(rel15->pduBitmap & 0x1)
+    {
+      set_ptrs_symb_idx(&dlPtrsSymPos,
+                          rel15->NrOfSymbols,
+                          rel15->StartSymbolIndex,
+                          1<<rel15->PTRSTimeDensity,
+                          rel15->dlDmrsSymbPos);
+      n_ptrs = (rel15->rbSize + rel15->PTRSFreqDensity - 1)/rel15->PTRSFreqDensity;
+    }
+    int16_t mod_ptrs[n_ptrs<<1] __attribute__ ((aligned(16)));
     
     /// CRC, coding, interleaving and rate matching
     AssertFatal(harq->pdu!=NULL,"harq->pdu is null\n");
@@ -306,9 +324,37 @@ uint8_t nr_generate_pdsch(PHY_VARS_gNB *gNB,
 #endif
         //FixMe l_prime should be updated here in the case of double DMRS config
 
+        /* calculate if current symbol is PTRS symbols */
+        ptrs_idx = 0;
+
+        if(rel15->pduBitmap & 0x1)
+        {         
+          ptrs_symbol = is_ptrs_symbol(l,dlPtrsSymPos);
+          if(ptrs_symbol)
+          {
+            /* PTRS QPSK Modulation for each OFDM symbol in a slot */
+            nr_modulation(pdsch_dmrs[l][0], (n_ptrs<<1), DMRS_MOD_ORDER, mod_ptrs);
+          }
+        }
         k = start_sc;
         // Loop Over SCs:
         for (int i=0; i<rel15->rbSize*NR_NB_SC_PER_RB; i++) {
+          /* check if cuurent RE is PTRS RE*/
+          is_ptrs_re=0;
+          /* check for PTRS symbol and set flag for PTRS RE */
+          if(ptrs_symbol){
+            is_ptrs_re = is_ptrs_subcarrier(k,
+                                            rel15->rnti,
+                                            ap,
+                                            rel15->dmrsConfigType,
+                                            rel15->PTRSFreqDensity,
+                                            rel15->rbSize,
+                                            rel15->PTRSReOffset,
+                                            start_sc,
+                                            frame_parms->ofdm_symbol_size);
+          }
+
+          /* Map DMRS Symbol */
           if ( ( dmrs_symbol_map & (1 << l) ) && (k == ((start_sc+get_dmrs_freq_idx(n, k_prime, delta, dmrs_Type))%(frame_parms->ofdm_symbol_size)))) {
             ((int16_t*)txdataF[ap])[((l*frame_parms->ofdm_symbol_size + k)<<1) + (2*txdataF_offset)] = (Wt[l_prime[0]]*Wf[k_prime]*amp*mod_dmrs[dmrs_idx<<1]) >> 15;
             ((int16_t*)txdataF[ap])[((l*frame_parms->ofdm_symbol_size + k)<<1) + 1 + (2*txdataF_offset)] = (Wt[l_prime[0]]*Wf[k_prime]*amp*mod_dmrs[(dmrs_idx<<1) + 1]) >> 15;
@@ -322,7 +368,18 @@ uint8_t nr_generate_pdsch(PHY_VARS_gNB *gNB,
             k_prime&=1;
             n+=(k_prime)?0:1;
           }
-	  
+          /* Map PTRS Symbol */
+          else if(is_ptrs_re){
+            ((int16_t*)txdataF[ap])[((l*frame_parms->ofdm_symbol_size + k)<<1) + (2*txdataF_offset)] = (beta_ptrs*amp*mod_ptrs[ptrs_idx<<1]) >> 15;
+            ((int16_t*)txdataF[ap])[((l*frame_parms->ofdm_symbol_size + k)<<1) + 1 + (2*txdataF_offset)] = (beta_ptrs*amp*mod_ptrs[(ptrs_idx<<1) + 1])>> 15;
+#ifdef DEBUG_DLSCH_MAPPING
+            printf("ptrs_idx %d\t l %d \t k %d \t k_prime %d \t n %d \t txdataF: %d %d\n",
+                   ptrs_idx, l, k, k_prime, n, ((int16_t*)txdataF[ap])[((l*frame_parms->ofdm_symbol_size + k)<<1) + (2*txdataF_offset)],
+                   ((int16_t*)txdataF[ap])[((l*frame_parms->ofdm_symbol_size + k)<<1) + 1 + (2*txdataF_offset)]);
+#endif
+            ptrs_idx++;
+          }
+          /* Map DATA Symbol */
           else {
             if( (!(dmrs_symbol_map & (1 << l))) || allowed_xlsch_re_in_dmrs_symbol(k,start_sc,rel15->numDmrsCdmGrpsNoData,dmrs_Type)) {
               ((int16_t*)txdataF[ap])[((l*frame_parms->ofdm_symbol_size + k)<<1) + (2*txdataF_offset)] = (amp * tx_layers[ap][m<<1]) >> 15;

openair2/LAYER2/NR_MAC_COMMON/nr_mac_common.c

@@ -2818,7 +2818,20 @@ bool set_dl_ptrs_values(NR_PTRS_DownlinkConfig_t *ptrs_config,
   /* If either or both of the parameters PT-RS time density (LPT-RS) and PT-RS frequency density (KPT-RS), shown in Table
    * 5.1.6.3-1 and Table 5.1.6.3-2, indicates that 'PT-RS not present', the UE shall assume that PT-RS is not present
    */
-  if((*K_ptrs !=2  || *K_ptrs !=4 ) || (*L_ptrs !=0 || *L_ptrs !=1 || *L_ptrs !=2  ))
+  if(*K_ptrs ==2  || *K_ptrs ==4 )
+  {
+    valid = true;
+  }
+  else
+  {
+    valid = false;
+    return valid;
+  }
+  if(*L_ptrs ==0 || *L_ptrs ==1 || *L_ptrs ==2  )
+  {
+    valid = true;
+  }
+  else
   {
     valid = false;
     return valid;