ensure minimum tbs. If it cant do it, increase mcs until it can.

srsenb/src/stack/mac/scheduler_harq.cc

@@ -268,9 +268,7 @@ void ul_harq_proc::new_tx(uint32_t tti_, int mcs, int tbs, ul_harq_proc::ul_allo
 
 void ul_harq_proc::new_retx(uint32_t tb_idx, uint32_t tti_, int* mcs, int* tbs, ul_harq_proc::ul_alloc_t alloc)
 {
-  if (alloc.L != allocation.L or alloc.RB_start != allocation.RB_start) {
-    is_adaptive = true;
-  }
+  is_adaptive = alloc.L != allocation.L or alloc.RB_start != allocation.RB_start;
   allocation  = alloc;
   new_retx_common(tb_idx, tti_, mcs, tbs);
 }

srsenb/src/stack/mac/scheduler_ue.cc

@@ -395,11 +395,17 @@ int sched_ue::generate_format1(dl_harq_proc*                     h,
       mcs = mcs0;
     }
 
+    // Ensure tbs >= MIN_DATA_TBS
+    while (tbs < MIN_DATA_TBS and mcs != carriers[cc_idx].max_mcs_dl) {
+      mcs++;
+      tbs = srslte_ra_tbs_from_idx(srslte_ra_tbs_idx_from_mcs(mcs, false), nof_prb) / 8;
+    }
     if (tbs < MIN_DATA_TBS) {
       log_h->warning("SCHED: Allocation of TBS=%d that does not account header\n", tbs);
       return 0;
     }
 
+    // Allocate DL Harq
     h->new_tx(user_mask, 0, tti_tx_dl, mcs, tbs, data->dci.location.ncce);
 
     int rem_tbs = tbs;
@@ -420,6 +426,7 @@ int sched_ue::generate_format1(dl_harq_proc*                     h,
       rem_tbs -= 2;
     }
 
+    // Allocate PDUs
     do {
       x = alloc_pdu(rem_tbs, &data->pdu[0][data->nof_pdu_elems[0]]);
       if (x) {