improve handling of MSG4 feedback in default PUCCH

openair2/LAYER2/NR_MAC_UE/mac_defs.h

@@ -162,7 +162,6 @@ typedef enum {
   UE_NOT_SYNC = 0,
   UE_SYNC,
   UE_PERFORMING_RA,
-  UE_WAIT_TX_ACK_MSG4,
   UE_CONNECTED
 } NR_UE_L2_STATE_t;
 

openair2/LAYER2/NR_MAC_UE/mac_proto.h

@@ -364,6 +364,9 @@ void nr_get_prach_resources(module_id_t mod_id,
                             NR_PRACH_RESOURCES_t *prach_resources,
                             NR_RACH_ConfigDedicated_t * rach_ConfigDedicated);
 
+void prepare_msg4_feedback(NR_UE_MAC_INST_t *mac, NR_UE_HARQ_STATUS_t *current_harq, int ack_nack);
+void configure_initial_pucch(PUCCH_sched_t *pucch, int res_ind);
+
 void init_RA(module_id_t mod_id,
              NR_PRACH_RESOURCES_t *prach_resources,
              NR_RACH_ConfigCommon_t *nr_rach_ConfigCommon,

openair2/LAYER2/NR_MAC_UE/nr_ra_procedures.c

@@ -894,7 +894,6 @@ void nr_ra_succeeded(const module_id_t mod_id, const uint8_t gNB_index, const fr
 
   if (ra->cfra) {
     LOG_I(MAC, "[UE %d][%d.%d][RAPROC] RA procedure succeeded. CF-RA: RAR successfully received.\n", mod_id, frame, slot);
-    mac->state = UE_CONNECTED;
     ra->RA_window_cnt = -1;
   } else {
     LOG_A(MAC, "[UE %d][%d.%d][RAPROC] RA procedure succeeded. CB-RA: Contention Resolution is successful.\n", mod_id, frame, slot);
@@ -902,12 +901,12 @@ void nr_ra_succeeded(const module_id_t mod_id, const uint8_t gNB_index, const fr
     mac->crnti = ra->t_crnti;
     ra->t_crnti = 0;
     LOG_D(MAC, "In %s: [UE %d][%d.%d] CB-RA: cleared contention resolution timer...\n", __FUNCTION__, mod_id, frame, slot);
-    mac->state = UE_WAIT_TX_ACK_MSG4;
   }
 
   LOG_D(MAC, "In %s: [UE %d] clearing RA_active flag...\n", __FUNCTION__, mod_id);
   ra->RA_active = 0;
   ra->ra_state = RA_SUCCEEDED;
+  mac->state = UE_CONNECTED;
   nr_mac_rrc_ra_ind(mod_id, frame, true);
 }
 
@@ -915,8 +914,8 @@ void nr_ra_succeeded(const module_id_t mod_id, const uint8_t gNB_index, const fr
 // according to section 5 of 3GPP TS 38.321 version 16.2.1 Release 16
 // todo:
 // - complete handling of received contention-based RA preamble
-void nr_ra_failed(uint8_t mod_id, uint8_t CC_id, NR_PRACH_RESOURCES_t *prach_resources, frame_t frame, int slot) {
-
+void nr_ra_failed(uint8_t mod_id, uint8_t CC_id, NR_PRACH_RESOURCES_t *prach_resources, frame_t frame, int slot)
+{
   NR_UE_MAC_INST_t *mac = get_mac_inst(mod_id);
   RA_config_t *ra = &mac->ra;
   // Random seed generation
@@ -950,5 +949,32 @@ void nr_ra_failed(uint8_t mod_id, uint8_t CC_id, NR_PRACH_RESOURCES_t *prach_res
     // Resetting RA window
     nr_get_RA_window(mac);
   }
+}
 
+void prepare_msg4_feedback(NR_UE_MAC_INST_t *mac, NR_UE_HARQ_STATUS_t *current_harq, int ack_nack)
+{
+  int sched_slot = current_harq->ul_slot;
+  int sched_frame = current_harq->ul_frame;
+  fapi_nr_ul_config_request_t *ul_config = get_ul_config_request(mac, sched_slot, 0);
+  pthread_mutex_lock(&ul_config->mutex_ul_config);
+  mac->nr_ue_emul_l1.num_harqs = 1;
+  AssertFatal(ul_config->number_pdus < FAPI_NR_UL_CONFIG_LIST_NUM,
+              "ul_config->number_pdus %d out of bounds\n",
+              ul_config->number_pdus);
+  fapi_nr_ul_config_pucch_pdu *pucch_pdu = &ul_config->ul_config_list[ul_config->number_pdus].pucch_config_pdu;
+  PUCCH_sched_t pucch = {0};
+  pucch.n_CCE = current_harq->n_CCE;
+  pucch.N_CCE = current_harq->N_CCE;
+  pucch.delta_pucch = current_harq->delta_pucch;
+  pucch.ack_payload = ack_nack;
+  pucch.n_harq = 1;
+  current_harq->active = false;
+  current_harq->ack_received = false;
+  nr_ue_configure_pucch(mac,
+                        sched_slot,
+                        mac->ra.t_crnti,
+                        &pucch,
+                        pucch_pdu);
+  fill_ul_config(ul_config, sched_frame, sched_slot, FAPI_NR_UL_CONFIG_TYPE_PUCCH);
+  pthread_mutex_unlock(&ul_config->mutex_ul_config);
 }

openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c

@@ -1262,7 +1262,6 @@ void set_harq_status(NR_UE_MAC_INST_t *mac,
                      int slot)
 {
   NR_UE_HARQ_STATUS_t *current_harq = &mac->dl_harq_info[harq_id];
-
   current_harq->active = true;
   current_harq->ack_received = false;
   current_harq->pucch_resource_indicator = pucch_id;
@@ -2172,6 +2171,19 @@ void multiplex_pucch_resource(NR_UE_MAC_INST_t *mac, PUCCH_sched_t *pucch, int n
   }
 }
 
+void configure_initial_pucch(PUCCH_sched_t *pucch, int res_ind)
+{
+  /* see TS 38.213 9.2.1  PUCCH Resource Sets */
+  int delta_PRI = res_ind;
+  int n_CCE_0 = pucch->n_CCE;
+  int N_CCE_0 = pucch->N_CCE;
+  if (N_CCE_0 == 0)
+    AssertFatal(1 == 0, "PUCCH No compatible pucch format found\n");
+  int r_PUCCH = ((2 * n_CCE_0) / N_CCE_0) + (2 * delta_PRI);
+  pucch->initial_pucch_id = r_PUCCH;
+  pucch->pucch_resource = NULL;
+}
+
 /*******************************************************************
 *
 * NAME :         get_downlink_ack
@@ -2356,18 +2368,10 @@ bool get_downlink_ack(NR_UE_MAC_INST_t *mac, frame_t frame, int slot, PUCCH_sche
   }
 
   NR_PUCCH_Config_t *pucch_Config = current_UL_BWP->pucch_Config;
-  if (mac->state == UE_WAIT_TX_ACK_MSG4 || !pucch_Config || !pucch_Config->resourceSetToAddModList
-      || pucch_Config->resourceSetToAddModList->list.array[0] == NULL) {
-    /* see TS 38.213 9.2.1  PUCCH Resource Sets */
-    int delta_PRI = res_ind;
-    int n_CCE_0 = pucch->n_CCE;
-    int N_CCE_0 = pucch->N_CCE;
-    if (N_CCE_0 == 0)
-      AssertFatal(1 == 0, "PUCCH No compatible pucch format found\n");
-    int r_PUCCH = ((2 * n_CCE_0) / N_CCE_0) + (2 * delta_PRI);
-    pucch->initial_pucch_id = r_PUCCH;
-    pucch->pucch_resource = NULL;
-  } else {
+  if (!pucch_Config || !pucch_Config->resourceSetToAddModList
+      || pucch_Config->resourceSetToAddModList->list.array[0] == NULL)
+    configure_initial_pucch(pucch, res_ind);
+  else {
     int resource_set_id = find_pucch_resource_set(mac, O_ACK);
     int n_list = pucch_Config->resourceSetToAddModList->list.count;
     AssertFatal(resource_set_id < n_list, "Invalid PUCCH resource set id %d\n", resource_set_id);
@@ -2381,7 +2385,7 @@ bool get_downlink_ack(NR_UE_MAC_INST_t *mac, frame_t frame, int slot, PUCCH_sche
     pucch->pucch_resource = acknack_resource;
     LOG_D(MAC, "frame %d slot %d pucch acknack payload %d\n", frame, slot, o_ACK);
   }
-  reverse_n_bits(&o_ACK,number_harq_feedback);
+  reverse_n_bits(&o_ACK, number_harq_feedback);
   pucch->ack_payload = o_ACK;
   pucch->n_harq = number_harq_feedback;
 
@@ -2833,7 +2837,8 @@ void nr_ue_send_sdu(nr_downlink_indication_t *dl_info, int pdu_id)
 {
   VCD_SIGNAL_DUMPER_DUMP_FUNCTION_BY_NAME(VCD_SIGNAL_DUMPER_FUNCTIONS_UE_SEND_SDU, VCD_FUNCTION_IN);
 
-  LOG_D(MAC, "In %s [%d.%d] Handling DLSCH PDU...\n", __FUNCTION__, dl_info->frame, dl_info->slot);
+  LOG_D(MAC, "In [%d.%d] Handling DLSCH PDU type %d\n",
+        dl_info->frame, dl_info->slot, dl_info->rx_ind->rx_indication_body[pdu_id].pdu_type);
 
   // Processing MAC PDU
   // it parses MAC CEs subheaders, MAC CEs, SDU subheaderds and SDUs

openair2/LAYER2/NR_MAC_UE/nr_ue_scheduler.c

@@ -60,8 +60,8 @@
 static prach_association_pattern_t prach_assoc_pattern;
 static void nr_ue_prach_scheduler(module_id_t module_idP, frame_t frameP, sub_frame_t slotP);
 
-void fill_ul_config(fapi_nr_ul_config_request_t *ul_config, frame_t frame_tx, int slot_tx, uint8_t pdu_type){
-
+void fill_ul_config(fapi_nr_ul_config_request_t *ul_config, frame_t frame_tx, int slot_tx, uint8_t pdu_type)
+{
   AssertFatal(ul_config->number_pdus < sizeof(ul_config->ul_config_list) / sizeof(ul_config->ul_config_list[0]),
               "Number of PDUS in ul_config = %d > ul_config_list num elements", ul_config->number_pdus);
   // clear ul_config for new frame/slot
@@ -91,8 +91,8 @@ void fill_scheduled_response(nr_scheduled_response_t *scheduled_response,
                              int cc_id,
                              frame_t frame,
                              int slot,
-                             void *phy_data){
-
+                             void *phy_data)
+{
   scheduled_response->dl_config  = dl_config;
   scheduled_response->ul_config  = ul_config;
   scheduled_response->tx_request = tx_request;
@@ -2137,8 +2137,6 @@ void nr_ue_pucch_scheduler(module_id_t module_idP, frame_t frameP, int slotP, vo
       fill_scheduled_response(&scheduled_response, NULL, ul_config, NULL, module_idP, 0 /*TBR fix*/, frameP, slotP, phy_data);
       if (mac->if_module != NULL && mac->if_module->scheduled_response != NULL)
         mac->if_module->scheduled_response(&scheduled_response);
-      if (mac->state == UE_WAIT_TX_ACK_MSG4)
-        mac->state = UE_CONNECTED;
     }
   }
 }

openair2/NR_UE_PHY_INTERFACE/NR_IF_Module.c

@@ -1103,15 +1103,20 @@ int8_t handle_csirs_measurements(module_id_t module_id, frame_t frame, int slot,
   return nr_ue_process_csirs_measurements(module_id, frame, slot, csirs_measurements);
 }
 
-void update_harq_status(module_id_t module_id, uint8_t harq_pid, uint8_t ack_nack) {
-
+void update_harq_status(module_id_t module_id, uint8_t harq_pid, uint8_t ack_nack)
+{
   NR_UE_MAC_INST_t *mac = get_mac_inst(module_id);
   NR_UE_HARQ_STATUS_t *current_harq = &mac->dl_harq_info[harq_pid];
 
   if (current_harq->active) {
+    LOG_D(PHY,"Updating harq_status for harq_id %d, ack/nak %d\n", harq_pid, current_harq->ack);
+    // we can prepare feedback for MSG4 in advance
+    if (mac->ra.ra_state == WAIT_CONTENTION_RESOLUTION)
+      prepare_msg4_feedback(mac, current_harq, ack_nack);
+    else {
       current_harq->ack = ack_nack;
       current_harq->ack_received = true;
-    LOG_T(PHY,"Updating harq_status for harq_id %d,ack/nak %d\n",harq_pid,current_harq->ack);
+    }
   }
   else {
     //shouldn't get here