Fixed for the PRB allocation issue assert in DLSCH scheduler

The following ASSERT is tirggered while testing 16 UE setup.

Assertion (NPRB>0 && (NPRB + RBstart <= BWPsize)) failed!
In PRBalloc_to_locationandbandwidth0() /home/ran/common/utils/nr/nr_common.c:286
Illegal NPRB/RBstart Configuration (1,48) for BWPsize 48

Corrected the get_start_stop_allocation calculation to fix the issue.
The implementation was wrong. The rbstop shall be the last rb that could
be allocated. Also the following two conditions are taken care

rbStart needs to be strictly smaller than rbStop

rbStart+rbSize needs to be smaller or equal to rbStop

The problem was that we confounded both conditions, so rbStart could
be equal to rbStop, which then leads to one PRB being allocated at the end.
Setting rbStop to BWPsize - 1 and making sure the above two conditions are
true does not make it lead to wrong allocations anymore.

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c

@@ -392,17 +392,17 @@ static void get_start_stop_allocation(gNB_MAC_INST *mac,
   // in which case the size of CORESET 0 shall be used if CORESET 0 is configured for the cell
   // and the size of initial DL bandwidth part shall be used if CORESET 0 is not configured for the cell.
   // TS 38.214 Section 5.1.2.2.2
-  *rbStop = dl_bwp->BWPSize;
+  *rbStop = dl_bwp->BWPSize - 1;
   *rbStart = 0; // start wrt BWPstart
   if (sched_ctrl->search_space->searchSpaceType->present == NR_SearchSpace__searchSpaceType_PR_common &&
       dl_bwp->dci_format == NR_DL_DCI_FORMAT_1_0) {
     if (mac->cset0_bwp_size != 0) {
       *rbStart = mac->cset0_bwp_start;
-      *rbStop = *rbStart + mac->cset0_bwp_size;
+      *rbStop = *rbStart + mac->cset0_bwp_size - 1;
     }
     else {
       *rbStart = UE->sc_info.initial_dl_BWPStart;
-      *rbStop = *rbStart + UE->sc_info.initial_dl_BWPSize;
+      *rbStop = *rbStart + UE->sc_info.initial_dl_BWPSize - 1;
     }
   }
 }
@@ -476,7 +476,7 @@ static bool allocate_dl_retransmission(module_id_t module_id,
         return false;
       }
 
-      while (rbStart + rbSize < rbStop &&
+      while (rbStart + rbSize <= rbStop &&
              (rballoc_mask[rbStart + rbSize] & slbitmap) == slbitmap &&
              rbSize < retInfo->rbSize)
         rbSize++;
@@ -493,7 +493,7 @@ static bool allocate_dl_retransmission(module_id_t module_id,
     while (rbStart < rbStop && (rballoc_mask[rbStart] & slbitmap) != slbitmap)
       rbStart++;
 
-    while (rbStart + rbSize < rbStop && (rballoc_mask[rbStart + rbSize] & slbitmap) == slbitmap)
+    while (rbStart + rbSize <= rbStop && (rballoc_mask[rbStart + rbSize] & slbitmap) == slbitmap)
       rbSize++;
 
     uint32_t new_tbs;
@@ -785,7 +785,7 @@ static void pf_dl(module_id_t module_id,
 
     uint16_t max_rbSize = 1;
 
-    while (rbStart + max_rbSize < rbStop && (rballoc_mask[rbStart + max_rbSize] & slbitmap) == slbitmap)
+    while (rbStart + max_rbSize <= rbStop && (rballoc_mask[rbStart + max_rbSize] & slbitmap) == slbitmap)
       max_rbSize++;
 
     sched_pdsch->dmrs_parms = get_dl_dmrs_params(scc,
@@ -1166,7 +1166,7 @@ void nr_schedule_ue_spec(module_id_t module_id,
     get_start_stop_allocation(gNB_mac, UE, &rbStart, &rbStop);
     dci_payload.frequency_domain_assignment.val = PRBalloc_to_locationandbandwidth0(pdsch_pdu->rbSize,
                                                                                     pdsch_pdu->rbStart - rbStart,
-                                                                                    rbStop - rbStart);
+                                                                                    rbStop - rbStart + 1);
     dci_payload.format_indicator = 1;
     dci_payload.time_domain_assignment.val = sched_pdsch->time_domain_allocation;
     dci_payload.mcs = sched_pdsch->mcs;