Fixing UE OFDM symbol generation

The CP length was hard coded for numerology 1

openair1/PHY/MODULATION/modulation_common.h

@@ -49,7 +49,7 @@ void PHY_ofdm_mod(int *input,
 
 
 void normal_prefix_mod(int32_t *txdataF,int32_t *txdata,uint8_t nsymb,LTE_DL_FRAME_PARMS *frame_parms);
-void nr_normal_prefix_mod(int32_t *txdataF,int32_t *txdata,uint8_t nsymb,NR_DL_FRAME_PARMS *frame_parms);
+void nr_normal_prefix_mod(int32_t *txdataF,int32_t *txdata,uint8_t nsymb,NR_DL_FRAME_PARMS *frame_parms, uint32_t slot);
 
 void do_OFDM_mod(int32_t **txdataF, int32_t **txdata, uint32_t frame,uint16_t next_slot, LTE_DL_FRAME_PARMS *frame_parms);
 

openair1/PHY/MODULATION/ofdm_mod.c

@@ -63,20 +63,62 @@ void normal_prefix_mod(int32_t *txdataF,int32_t *txdata,uint8_t nsymb,LTE_DL_FRA
   
 }
 
-void nr_normal_prefix_mod(int32_t *txdataF,int32_t *txdata,uint8_t nsymb,NR_DL_FRAME_PARMS *frame_parms)
+void nr_normal_prefix_mod(int32_t *txdataF,int32_t *txdata,uint8_t nsymb,NR_DL_FRAME_PARMS *frame_parms, uint32_t slot)
 {
-  PHY_ofdm_mod(txdataF,        // input
-	       txdata,         // output
-	       frame_parms->ofdm_symbol_size,                
-	       1,                 // number of symbols
-	       frame_parms->nb_prefix_samples0,               // number of prefix samples
-	       CYCLIC_PREFIX);
-  PHY_ofdm_mod(txdataF+frame_parms->ofdm_symbol_size,        // input
-	       txdata + frame_parms->ofdm_symbol_size + frame_parms->nb_prefix_samples0,         // output
-	       frame_parms->ofdm_symbol_size,                
-	       nsymb - 1,
-	       frame_parms->nb_prefix_samples,               // number of prefix samples
-	       CYCLIC_PREFIX);  
+  // This function works only slot wise. For more generic symbol generation refer nr_feptx0()
+  if (frame_parms->numerology_index != 0) { // case where numerology != 0
+    if (!(slot%(frame_parms->slots_per_subframe/2))) {
+      PHY_ofdm_mod(txdataF,
+             txdata,
+             frame_parms->ofdm_symbol_size,
+             1,
+             frame_parms->nb_prefix_samples0,
+             CYCLIC_PREFIX);
+      PHY_ofdm_mod(txdataF+frame_parms->ofdm_symbol_size,
+             txdata + frame_parms->ofdm_symbol_size + frame_parms->nb_prefix_samples0,
+             frame_parms->ofdm_symbol_size,
+             nsymb - 1,
+             frame_parms->nb_prefix_samples,
+             CYCLIC_PREFIX);
+    }
+    else {
+      PHY_ofdm_mod(txdataF,
+             txdata,
+             frame_parms->ofdm_symbol_size,
+             nsymb,
+             frame_parms->nb_prefix_samples,
+             CYCLIC_PREFIX);
+    }
+  }
+  else { // numerology = 0, longer CP for every 7th symbol
+      PHY_ofdm_mod(txdataF,
+             txdata,
+             frame_parms->ofdm_symbol_size,
+             1,
+             frame_parms->nb_prefix_samples0,
+             CYCLIC_PREFIX);
+      PHY_ofdm_mod(txdataF+frame_parms->ofdm_symbol_size,
+             txdata + frame_parms->ofdm_symbol_size + frame_parms->nb_prefix_samples0,
+             frame_parms->ofdm_symbol_size,
+             6,
+             frame_parms->nb_prefix_samples,
+             CYCLIC_PREFIX);
+      PHY_ofdm_mod(txdataF + 7*frame_parms->ofdm_symbol_size,
+             txdata + 6*(frame_parms->ofdm_symbol_size+frame_parms->nb_prefix_samples) +
+                    frame_parms->ofdm_symbol_size + frame_parms->nb_prefix_samples0,
+             frame_parms->ofdm_symbol_size,
+             1,
+             frame_parms->nb_prefix_samples0,
+             CYCLIC_PREFIX);
+      PHY_ofdm_mod(txdataF + 8*frame_parms->ofdm_symbol_size,
+             txdata + 6*(frame_parms->ofdm_symbol_size+frame_parms->nb_prefix_samples) +
+                    2*(frame_parms->ofdm_symbol_size + frame_parms->nb_prefix_samples0),
+             frame_parms->ofdm_symbol_size,
+             6,
+             frame_parms->nb_prefix_samples,
+             CYCLIC_PREFIX);
+  }
+
 }
 
 void PHY_ofdm_mod(int *input,                       /// pointer to complex input

openair1/PHY/NR_UE_TRANSPORT/nr_ulsch_ue.c

@@ -525,7 +525,8 @@ uint8_t nr_ue_pusch_common_procedures(PHY_VARS_NR_UE *UE,
       nr_normal_prefix_mod(txdataF[ap],
                            &txdata[ap][tx_offset],
                            14,
-                           frame_parms);
+                           frame_parms,
+                           slot);
     }
   }
 

openair1/SCHED_NR/nr_ru_procedures.c

@@ -122,6 +122,7 @@ void nr_feptx0(RU_t *ru,int tti_tx,int first_symbol, int num_symbols, int aa) {
                        fp->nb_prefix_samples,
                        CYCLIC_PREFIX);
           slot_offset += fp->nb_prefix_samples+fp->ofdm_symbol_size;
+          slot_offsetF += fp->ofdm_symbol_size;
         }
         else {
           PHY_ofdm_mod(&ru->common.txdataF_BF[aa][slot_offsetF],
@@ -131,6 +132,7 @@ void nr_feptx0(RU_t *ru,int tti_tx,int first_symbol, int num_symbols, int aa) {
                        fp->nb_prefix_samples0,
                        CYCLIC_PREFIX);
           slot_offset += fp->nb_prefix_samples0+fp->ofdm_symbol_size;
+          slot_offsetF += fp->ofdm_symbol_size;
         }
       }
     }

openair1/SIMULATION/NR_PHY/dlsim.c

@@ -1046,7 +1046,8 @@ int main(int argc, char **argv)
             nr_normal_prefix_mod(&gNB->common_vars.txdataF[aa][txdataF_offset],
                                  &txdata[aa][tx_offset],
                                  14,
-                                 frame_parms);
+                                 frame_parms,
+                                 slot);
           }
         }