Consider retransmissions in the preprocessor

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c

@@ -513,13 +513,46 @@ void nr_simple_dlsch_preprocessor(module_id_t module_id,
       module_id, UE_id, frame, slot, num_slots_per_tdd, &sched_ctrl->pucch_sched_idx);
   AssertFatal(sched_ctrl->pucch_sched_idx >= 0, "no uplink slot for PUCCH found!\n");
 
+  uint8_t *vrb_map = RC.nrmac[module_id]->common_channels[CC_id].vrb_map;
+  const int current_harq_pid = sched_ctrl->current_harq_pid;
+  NR_UE_harq_t *harq = &sched_ctrl->harq_processes[current_harq_pid];
+  NR_UE_ret_info_t *retInfo = &sched_ctrl->retInfo[current_harq_pid];
+  const uint16_t bwpSize = NRRIV2BW(sched_ctrl->active_bwp->bwp_Common->genericParameters.locationAndBandwidth, 275);
+  int rbStart = NRRIV2PRBOFFSET(sched_ctrl->active_bwp->bwp_Common->genericParameters.locationAndBandwidth, 275);
+
+  if (harq->round != 0) { /* retransmission */
+    sched_ctrl->time_domain_allocation = retInfo->time_domain_allocation;
+
+    /* ensure that there is a free place for RB allocation */
+    int rbSize = 0;
+    while (rbSize < retInfo->rbSize) {
+      rbStart += rbSize; /* last iteration rbSize was not enough, skip it */
+      rbSize = 0;
+      while (rbStart < bwpSize && vrb_map[rbStart]) rbStart++;
+      if (rbStart >= bwpSize) {
+        LOG_E(MAC,
+              "cannot allocate retransmission for UE %d/RNTI %04x: no resources\n",
+              UE_id,
+              rnti);
+        return;
+      }
+      while (rbStart + rbSize < bwpSize
+             && !vrb_map[rbStart + rbSize]
+             && rbSize < retInfo->rbSize)
+        rbSize++;
+    }
+    sched_ctrl->rbSize = retInfo->rbSize;
+    sched_ctrl->rbStart = rbStart;
+
+    /* MCS etc: just reuse from previous scheduling opportunity */
+    sched_ctrl->mcsTableIdx = retInfo->mcsTableIdx;
+    sched_ctrl->mcs = retInfo->mcs;
+    sched_ctrl->numDmrsCdmGrpsNoData = retInfo->numDmrsCdmGrpsNoData;
+  } else {
     // Time-domain allocation
     sched_ctrl->time_domain_allocation = 2;
 
     // Freq-demain allocation
-  uint8_t *vrb_map = RC.nrmac[module_id]->common_channels[CC_id].vrb_map;
-  const uint16_t bwpSize = NRRIV2BW(sched_ctrl->active_bwp->bwp_Common->genericParameters.locationAndBandwidth, 275);
-  int rbStart = NRRIV2PRBOFFSET(sched_ctrl->active_bwp->bwp_Common->genericParameters.locationAndBandwidth, 275);
     while (rbStart < bwpSize && vrb_map[rbStart]) rbStart++;
     int rbSize = 1;
     while (rbStart + rbSize < bwpSize && !vrb_map[rbStart + rbSize]) rbSize++;
@@ -527,10 +560,6 @@ void nr_simple_dlsch_preprocessor(module_id_t module_id,
     sched_ctrl->rbSize = rbSize;
     sched_ctrl->rbStart = rbStart;
 
-  /* mark the corresponding RBs as used */
-  for (int rb = 0; rb < sched_ctrl->rbSize; rb++)
-    vrb_map[rb + sched_ctrl->rbStart] = 1;
-
     // modulation scheme
     sched_ctrl->mcsTableIdx = 0;
     sched_ctrl->mcs = 9;
@@ -552,6 +581,11 @@ void nr_simple_dlsch_preprocessor(module_id_t module_id,
                        1 /* nrOfLayers */)
         >> 3;
     AssertFatal(TBS != 0, "TBS is zero but requested %d RBs!\n", sched_ctrl->rbSize);
+  }
+
+  /* mark the corresponding RBs as used */
+  for (int rb = 0; rb < sched_ctrl->rbSize; rb++)
+    vrb_map[rb + sched_ctrl->rbStart] = 1;
 }
 
 void nr_schedule_ue_spec(module_id_t module_id,