basic simulator: support TDD mode

For whatever reason we need N_TA_offset to be 0 for the basic simulator
to function properly.

This is more a hack than a proper solution. More analysis is needed
to understand what happens and what should be really done.

openair1/PHY/INIT/lte_param_init.c

@@ -169,6 +169,13 @@ void lte_param_init(PHY_VARS_eNB **eNBp,
   }
   else ru->N_TA_offset=0;
 
+#if BASIC_SIMULATOR
+  /* this is required for the basic simulator in TDD mode
+   * TODO: find a proper cleaner solution
+   */
+  UE->N_TA_offset = 0;
+#endif
+
   printf("Done lte_param_init\n");
 
 

targets/RT/USER/lte-ru.c

@@ -1456,6 +1456,12 @@ int setup_RU_buffers(RU_t *ru) {
     if      (frame_parms->N_RB_DL == 100) ru->N_TA_offset = 624;
     else if (frame_parms->N_RB_DL == 50)  ru->N_TA_offset = 624/2;
     else if (frame_parms->N_RB_DL == 25)  ru->N_TA_offset = 624/4;
+#if BASIC_SIMULATOR
+    /* this is required for the basic simulator in TDD mode
+     * TODO: find a proper cleaner solution
+     */
+    ru->N_TA_offset = 0;
+#endif
   } 
   if (ru->openair0_cfg.mmapped_dma == 1) {
     // replace RX signal buffers with mmaped HW versions

targets/RT/USER/lte-ue.c

@@ -333,6 +333,13 @@ void init_UE(int nb_inst,int eMBMS_active, int uecap_xer_in, int timing_correcti
     }
     else UE->N_TA_offset = 0;
 
+#if BASIC_SIMULATOR
+    /* this is required for the basic simulator in TDD mode
+     * TODO: find a proper cleaner solution
+     */
+    UE->N_TA_offset = 0;
+#endif
+
     if (simL1flag == 1) init_ue_devices(UE);
     LOG_I(PHY,"Intializing UE Threads for instance %d (%p,%p)...\n",inst,PHY_vars_UE_g[inst],PHY_vars_UE_g[inst][0]);
     init_UE_threads(inst);