adding comments for transform precoding

openair1/PHY/NR_ESTIMATION/nr_ul_channel_estimation.c

@@ -129,6 +129,7 @@ int nr_pusch_channel_estimation(PHY_VARS_gNB *gNB,
 
   //------------------generate DMRS------------------//
 
+  // transform precoding = 1 means disabled
   if (pusch_pdu->transform_precoding == 1) {
     nr_pusch_dmrs_rx(gNB, Ns, gNB->nr_gold_pusch_dmrs[pusch_pdu->scid][Ns][symbol], &pilot[0], 1000, 0, nb_rb_pusch,
                      (pusch_pdu->bwp_start + pusch_pdu->rb_start)*NR_NB_SC_PER_RB, pusch_pdu->dmrs_config_type);

openair1/PHY/NR_TRANSPORT/nr_ulsch_demodulation.c

@@ -1317,6 +1317,7 @@ int nr_rx_pusch(PHY_VARS_gNB *gNB,
                              rel15_ul->rb_size);
       stop_meas(&gNB->ulsch_mrc_stats);
 
+      // transform precoding = 0 means enabled
       if (rel15_ul->transform_precoding == 0) {
 
       #ifdef __AVX2__

openair1/PHY/NR_UE_TRANSPORT/nr_ulsch_ue.c

@@ -252,7 +252,7 @@ void nr_ue_ulsch_procedures(PHY_VARS_NR_UE *UE,
   uint8_t u = 0, v = 0;
   int16_t *dmrs_seq = NULL;
 
-  // enbaled
+  // if  transform precoding is enbaled (value 0)
   if (pusch_pdu->transform_precoding == 0) {
 
     uint32_t nb_re_pusch=nb_rb * NR_NB_SC_PER_RB;
@@ -354,7 +354,7 @@ void nr_ue_ulsch_procedures(PHY_VARS_NR_UE *UE,
       if ((ul_dmrs_symb_pos >> l) & 0x01) {
         is_dmrs_sym = 1;
 
-        // disabled
+        // transform precoding disabled (value 1)
         if (pusch_pdu->transform_precoding == 1){
         
           if (dmrs_type == pusch_dmrs_type1)
@@ -405,7 +405,7 @@ void nr_ue_ulsch_procedures(PHY_VARS_NR_UE *UE,
         }
 
         if (is_dmrs == 1) {
-          // if enabled
+          // if transform precoding is enabled
           if (pusch_pdu->transform_precoding == 0) {
           
             ((int16_t*)txdataF[ap])[(sample_offsetF)<<1] = (Wt[l_prime[0]]*Wf[k_prime]*AMP*dmrs_seq[2*dmrs_idx]) >> 15;

openair1/SIMULATION/NR_PHY/ulsim.c

@@ -566,7 +566,7 @@ int main(int argc, char **argv)
 
     case 'Z':
 
-      transform_precoding = 0; 
+      transform_precoding = 0; // enabled
       num_dmrs_cdm_grps_no_data = 2;
       mcs_table = 3;
       
@@ -840,6 +840,7 @@ int main(int argc, char **argv)
   uint16_t number_dmrs_symbols = get_dmrs_symbols_in_slot(l_prime_mask, nb_symb_sch);
   uint8_t  nb_re_dmrs          = (dmrs_config_type == pusch_dmrs_type1) ? 6 : 4;
 
+  // if transform precoding is enabled
   if (transform_precoding == 0) {
 
     AssertFatal(enable_ptrs == 0, "PTRS NOT SUPPORTED IF TRANSFORM PRECODING IS ENABLED\n");
@@ -1045,6 +1046,7 @@ int main(int argc, char **argv)
       pusch_pdu->pusch_ptrs.ptrs_ports_list   = (nfapi_nr_ptrs_ports_t *) malloc(2*sizeof(nfapi_nr_ptrs_ports_t));
       pusch_pdu->pusch_ptrs.ptrs_ports_list[0].ptrs_re_offset = 0;
 
+      // if transform precoding is enabled
       if (transform_precoding == 0) {
 
         pusch_pdu->dfts_ofdm.low_papr_group_number = *scc->physCellId % 30; // U as defined in 38.211 section 6.4.1.1.1.2 
@@ -1105,6 +1107,7 @@ int main(int argc, char **argv)
 
       ul_config.ul_config_list[0].pusch_config_pdu.transform_precoding = transform_precoding;
 
+      // if transform precoding is enabled
       if (transform_precoding == 0) {
    
         ul_config.ul_config_list[0].pusch_config_pdu.dfts_ofdm.low_papr_group_number = *scc->physCellId % 30;// U as defined in 38.211 section 6.4.1.1.1.2