Store selected MCS in UE iterator

PF uses MCS and average throughput to decide which UE to schedule. Thus,
the first loop selects the MCS, and the second does the main UE
allocation after sorting by priority, depending on the MCS.

A follow-up commit will remove sched_pusch from NR_UE_sched_ctrl_t.
Thus, we cannot rely on sched_ctrl to store the MCS in the first loop,
and look it up from there in the second. Instead, store it as part of
the UE iterator data, and take it from there.

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c

@@ -1839,6 +1839,7 @@ static uint32_t ul_pf_tbs[5][29]; // pre-computed, approximate TBS values for PF
 typedef struct UEsched_s {
   float coef;
   NR_UE_info_t * UE;
+  int selected_mcs;
 } UEsched_t;
 
 static int comparator(const void *p, const void *q) {
@@ -1964,12 +1965,12 @@ static void pf_ul(module_id_t module_id,
     const NR_bler_options_t *bo = &nrmac->ul_bler;
     const int max_mcs_table = (current_BWP->mcs_table == 0 || current_BWP->mcs_table == 2) ? 28 : 27;
     const int max_mcs = min(bo->max_mcs, max_mcs_table); /* no per-user maximum MCS yet */
+    int selected_mcs;
     if (bo->harq_round_max == 1) {
-      sched_pusch->mcs = max_mcs;
-      sched_ctrl->ul_bler_stats.mcs = sched_pusch->mcs;
+      selected_mcs = sched_ctrl->ul_bler_stats.mcs = max_mcs;
     } else {
-      sched_pusch->mcs = get_mcs_from_bler(bo, stats, &sched_ctrl->ul_bler_stats, max_mcs, frame);
-      LOG_D(NR_MAC, "%d.%d starting mcs %d bler %f\n", frame, slot, sched_pusch->mcs, sched_ctrl->ul_bler_stats.bler);
+      selected_mcs = get_mcs_from_bler(bo, stats, &sched_ctrl->ul_bler_stats, max_mcs, frame);
+      LOG_D(NR_MAC, "%d.%d starting mcs %d bler %f\n", frame, slot, selected_mcs, sched_ctrl->ul_bler_stats.bler);
     }
     /* Schedule UE on SR or UL inactivity and no data (otherwise, will be scheduled
      * based on data to transmit) */
@@ -2032,6 +2033,7 @@ static void pf_ul(module_id_t module_id,
       fill_pdcch_vrb_map(nrmac, CC_id, &sched_ctrl->sched_pdcch, CCEIndex, sched_ctrl->aggregation_level, dci_beam.idx);
 
       NR_sched_pusch_t *sched_pusch = &sched_ctrl->sched_pusch;
+      sched_pusch->mcs = selected_mcs;
       update_ul_ue_R_Qm(sched_pusch->mcs, current_BWP->mcs_table, current_BWP->pusch_Config, &sched_pusch->R, &sched_pusch->Qm);
       sched_pusch->rbStart = rbStart;
       sched_pusch->rbSize = min_rb;
@@ -2077,7 +2079,7 @@ static void pf_ul(module_id_t module_id,
 
     /* Create UE_sched for UEs eligibale for new data transmission*/
     /* Calculate coefficient*/
-    const uint32_t tbs = ul_pf_tbs[current_BWP->mcs_table][sched_pusch->mcs];
+    const uint32_t tbs = ul_pf_tbs[current_BWP->mcs_table][selected_mcs];
     float coeff_ue = (float) tbs / UE->ul_thr_ue;
     LOG_D(NR_MAC, "[UE %04x][%4d.%2d] b %d, ul_thr_ue %f, tbs %d, coeff_ue %f\n",
           UE->rnti,
@@ -2089,6 +2091,7 @@ static void pf_ul(module_id_t module_id,
           coeff_ue);
     UE_sched[curUE].coef = coeff_ue;
     UE_sched[curUE].UE = UE;
+    UE_sched[curUE].selected_mcs = selected_mcs;
     curUE++;
   }
 
@@ -2192,6 +2195,7 @@ static void pf_ul(module_id_t module_id,
 
     /* Calculate the current scheduling bytes */
     const int B = cmax(sched_ctrl->estimated_ul_buffer - sched_ctrl->sched_ul_bytes, 0);
+    sched_pusch->mcs = iterator->selected_mcs;
     /* adjust rbSize and MCS according to PHR and BPRE */
     if(sched_ctrl->pcmax != 0 || sched_ctrl->ph != 0) // verify if the PHR related parameter have been initialized
       nr_ue_max_mcs_min_rb(current_BWP->scs, sched_ctrl->ph, sched_pusch, current_BWP, min_rb, B, &max_rbSize, &sched_pusch->mcs);