fix timing advance from msg2/rar

nfapi/open-nFAPI/nfapi/public_inc/fapi_nr_ue_interface.h

@@ -547,6 +547,7 @@ typedef struct {
  int ta_frame;
  int ta_slot;
  int ta_command;
+ bool is_rar;
 } fapi_nr_ta_command_pdu;
 
 typedef struct {

openair1/SCHED_NR_UE/fapi_nr_ue_l1.c

@@ -320,7 +320,7 @@ static void configure_dlsch(NR_UE_DLSCH_t *dlsch0,
   }
 }
 
-void configure_ta_command(PHY_VARS_NR_UE *ue, fapi_nr_ta_command_pdu *ta_command_pdu)
+static void configure_ta_command(PHY_VARS_NR_UE *ue, fapi_nr_ta_command_pdu *ta_command_pdu)
 {
 
   /* Time Alignment procedure
@@ -365,13 +365,19 @@ void configure_ta_command(PHY_VARS_NR_UE *ue, fapi_nr_ta_command_pdu *ta_command
   const double t_subframe = 1.0; // subframe duration of 1 msec
   const int ul_tx_timing_adjustment = 1 + (int)ceil(slots_per_subframe*(N_t_1 + N_t_2 + N_TA_max + 0.5)/t_subframe);
 
-  ue->ta_slot = (ta_command_pdu->ta_slot + ul_tx_timing_adjustment) % slots_per_frame;
+  if (ta_command_pdu->is_rar) {
-  if (ta_command_pdu->ta_slot + ul_tx_timing_adjustment > slots_per_frame)
+    ue->ta_slot = ta_command_pdu->ta_slot;
-    ue->ta_frame = (ta_command_pdu->ta_frame + 1) % 1024;
-  else
     ue->ta_frame = ta_command_pdu->ta_frame;
-
+    ue->timing_advance = 0;
-  ue->ta_command = ta_command_pdu->ta_command;
+    ue->ta_command = ta_command_pdu->ta_command + 31; // To use TA adjustment algo in ue_ta_procedures()
+  } else {
+    ue->ta_slot = (ta_command_pdu->ta_slot + ul_tx_timing_adjustment) % slots_per_frame;
+    if (ta_command_pdu->ta_slot + ul_tx_timing_adjustment > slots_per_frame)
+      ue->ta_frame = (ta_command_pdu->ta_frame + 1) % 1024;
+    else
+      ue->ta_frame = ta_command_pdu->ta_frame;
+    ue->ta_command = ta_command_pdu->ta_command;
+  }
   LOG_D(PHY,"TA command received in Frame.Slot %d.%d -- Starting UL time alignment procedures. TA update will be applied at frame %d slot %d\n",
         ta_command_pdu->ta_frame, ta_command_pdu->ta_slot, ue->ta_frame, ue->ta_slot);
 }

openair1/SCHED_NR_UE/phy_procedures_nr_ue.c

@@ -232,15 +232,14 @@ int get_tx_amp_prach(int power_dBm, int power_max_dBm, int N_RB_UL){
 // - If the current tx frame and slot match the TA configuration
 //   then timing advance is processed and set to be applied in the next UL transmission
 // - Application of timing adjustment according to TS 38.213 p4.2
-// todo:
 // - handle RAR TA application as per ch 4.2 TS 38.213
 void ue_ta_procedures(PHY_VARS_NR_UE *ue, int slot_tx, int frame_tx)
 {
   if (frame_tx == ue->ta_frame && slot_tx == ue->ta_slot) {
-
     uint16_t ofdm_symbol_size = ue->frame_parms.ofdm_symbol_size;
 
-    // convert time factor "16 * 64 * T_c / (2^mu)" in N_TA calculation in TS38.213 section 4.2 to samples by multiplying with samples per second
+    // convert time factor "16 * 64 * T_c / (2^mu)" in N_TA calculation in TS38.213 section 4.2 to samples by multiplying with
+    // samples per second
     //   16 * 64 * T_c            / (2^mu) * samples_per_second
     // = 16 * T_s                 / (2^mu) * samples_per_second
     // = 16 * 1 / (15 kHz * 2048) / (2^mu) * (15 kHz * 2^mu * ofdm_symbol_size)
@@ -250,7 +249,8 @@ void ue_ta_procedures(PHY_VARS_NR_UE *ue, int slot_tx, int frame_tx)
 
     ue->timing_advance += (ue->ta_command - 31) * bw_scaling;
 
-    LOG_D(PHY, "[UE %d] [%d.%d] Got timing advance command %u from MAC, new value is %d\n",
+    LOG_D(PHY,
+          "[UE %d] [%d.%d] Got timing advance command %u from MAC, new value is %d\n",
           ue->Mod_id,
           frame_tx,
           slot_tx,

openair1/SIMULATION/NR_PHY/ulsim.c

@@ -552,6 +552,8 @@ int main(int argc, char *argv[])
   gNB = RC.gNB[0];
   gNB->ofdm_offset_divisor = UINT_MAX;
   gNB->num_pusch_symbols_per_thread = 1;
+  gNB->RU_list[0] = calloc(1, sizeof(**gNB->RU_list));
+  gNB->RU_list[0]->rfdevice.openair0_cfg = openair0_cfg;
 
   initFloatingCoresTpool(threadCnt, &gNB->threadPool, false, "gNB-tpool");
   initNotifiedFIFO(&gNB->respDecode);

openair2/LAYER2/NR_MAC_UE/mac_defs.h

@@ -384,11 +384,16 @@ typedef struct {
   short ssb_rsrp_dBm;
 } NR_SSB_meas_t;
 
+typedef enum ta_type {
+  no_ta = 0,
+  adjustment_ta,
+  rar_ta,
+} ta_type_t;
+
 typedef struct NR_UL_TIME_ALIGNMENT {
   /// TA command and TAGID received from the gNB
-  bool ta_apply;
+  ta_type_t ta_apply;
   int ta_command;
-  int ta_total;
   uint32_t tag_id;
   int frame;
   int slot;

openair2/LAYER2/NR_MAC_UE/mac_proto.h

@@ -401,7 +401,6 @@ and fills the PRACH PDU per each FD occasion.
 void nr_ue_pucch_scheduler(NR_UE_MAC_INST_t *mac, frame_t frameP, int slotP, void *phy_data);
 void nr_schedule_csirs_reception(NR_UE_MAC_INST_t *mac, int frame, int slot);
 void nr_schedule_csi_for_im(NR_UE_MAC_INST_t *mac, int frame, int slot);
-void schedule_ta_command(fapi_nr_dl_config_request_t *dl_config, NR_UL_TIME_ALIGNMENT_t *ul_time_alignment);
 
 /* \brief This function schedules the Msg3 transmission
 @param

openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c

@@ -3722,12 +3722,11 @@ void nr_ue_process_mac_pdu(NR_UE_MAC_INST_t *mac, nr_downlink_indication_t *dl_i
         const int tag = ((NR_MAC_CE_TA *)pduP)[1].TAGID;
 
         NR_UL_TIME_ALIGNMENT_t *ul_time_alignment = &mac->ul_time_alignment;
-        ul_time_alignment->ta_total += ta - 31;
         ul_time_alignment->tag_id = tag;
         ul_time_alignment->ta_command = ta;
         ul_time_alignment->frame = frameP;
         ul_time_alignment->slot = slot;
-        ul_time_alignment->ta_apply = true;
+        ul_time_alignment->ta_apply = adjustment_ta;
         /*
         #ifdef DEBUG_HEADER_PARSING
         LOG_D(MAC, "[UE] CE %d : UE Timing Advance : %d\n", i, pduP[1]);
@@ -3735,21 +3734,9 @@ void nr_ue_process_mac_pdu(NR_UE_MAC_INST_t *mac, nr_downlink_indication_t *dl_i
         */
 
         if (ta == 31)
-          LOG_D(NR_MAC, "[%d.%d] Received TA_COMMAND %u TAGID %u CC_id %d TA total %d\n",
+          LOG_D(NR_MAC, "[%d.%d] Received TA_COMMAND %u TAGID %u CC_id %d \n", frameP, slot, ta, tag, CC_id);
-                frameP,
-                slot,
-                ta,
-                tag,
-                CC_id,
-                ul_time_alignment->ta_total);
         else
-          LOG_I(NR_MAC, "[%d.%d] Received TA_COMMAND %u TAGID %u CC_id %d TA total %d\n",
+          LOG_I(NR_MAC, "[%d.%d] Received TA_COMMAND %u TAGID %u CC_id %d \n", frameP, slot, ta, tag, CC_id);
-                frameP,
-                slot,
-                ta,
-                tag,
-                CC_id,
-                ul_time_alignment->ta_total);
 
         break;
       case DL_SCH_LCID_CON_RES_ID:
@@ -4129,9 +4116,9 @@ static void nr_ue_process_rar(NR_UE_MAC_INST_t *mac, nr_downlink_indication_t *d
     // TA command
     NR_UL_TIME_ALIGNMENT_t *ul_time_alignment = &mac->ul_time_alignment;
     const int ta = rar->TA2 + (rar->TA1 << 5);
-    ul_time_alignment->ta_command = 31 + ta;
+    ul_time_alignment->ta_command = ta;
-    ul_time_alignment->ta_total = ta;
+    ul_time_alignment->ta_apply = rar_ta;
-    ul_time_alignment->ta_apply = true;
+
     LOG_W(MAC, "received TA command %d\n", 31 + ta);
 #ifdef DEBUG_RAR
     // CSI
@@ -4221,6 +4208,8 @@ static void nr_ue_process_rar(NR_UE_MAC_INST_t *mac, nr_downlink_indication_t *d
       return;
     }
     ret = nr_ue_pusch_scheduler(mac, is_Msg3, frame, slot, &frame_tx, &slot_tx, tda_info.k2);
+    ul_time_alignment->frame = frame_tx;
+    ul_time_alignment->slot = slot_tx;
 
     if (ret != -1) {
       uint16_t rnti = mac->crnti;

openair2/LAYER2/NR_MAC_UE/nr_ue_scheduler.c

@@ -58,6 +58,7 @@
 //#define SRS_DEBUG
 
 static void nr_ue_prach_scheduler(NR_UE_MAC_INST_t *mac, frame_t frameP, sub_frame_t slotP);
+static void schedule_ta_command(fapi_nr_dl_config_request_t *dl_config, NR_UL_TIME_ALIGNMENT_t *ul_time_alignment);
 
 fapi_nr_ul_config_request_pdu_t *lockGet_ul_config(NR_UE_MAC_INST_t *mac, frame_t frame_tx, int slot_tx, uint8_t pdu_type)
 {
@@ -1018,7 +1019,7 @@ void nr_ue_dl_scheduler(NR_UE_MAC_INST_t *mac, nr_downlink_indication_t *dl_info
 
   ue_dci_configuration(mac, dl_config, rx_frame, rx_slot);
 
-  if (mac->ul_time_alignment.ta_apply)
+  if (mac->ul_time_alignment.ta_apply != no_ta)
     schedule_ta_command(dl_config, &mac->ul_time_alignment);
   if (mac->state == UE_CONNECTED) {
     nr_schedule_csirs_reception(mac, rx_frame, rx_slot);
@@ -3354,15 +3355,16 @@ uint8_t nr_ue_get_sdu(NR_UE_MAC_INST_t *mac,
   return num_sdus > 0 ? 1 : 0;
 }
 
-void schedule_ta_command(fapi_nr_dl_config_request_t *dl_config, NR_UL_TIME_ALIGNMENT_t *ul_time_alignment)
+static void schedule_ta_command(fapi_nr_dl_config_request_t *dl_config, NR_UL_TIME_ALIGNMENT_t *ul_time_alignment)
 {
   fapi_nr_ta_command_pdu *ta = &dl_config->dl_config_list[dl_config->number_pdus].ta_command_pdu;
   ta->ta_frame = ul_time_alignment->frame;
   ta->ta_slot = ul_time_alignment->slot;
+  ta->is_rar = ul_time_alignment->ta_apply == rar_ta;
   ta->ta_command = ul_time_alignment->ta_command;
   dl_config->dl_config_list[dl_config->number_pdus].pdu_type = FAPI_NR_CONFIG_TA_COMMAND;
   dl_config->number_pdus += 1;
-  ul_time_alignment->ta_apply = false;
+  ul_time_alignment->ta_apply = no_ta;
 }
 
 uint32_t nr_get_pbr(long prioritizedbitrate)