sched,nr: increase max R to 0.93 to enable mcs=28

srsenb/src/stack/mac/nr/sched_nr_grant_allocator.cc

@@ -244,6 +244,7 @@ alloc_result bwp_slot_allocator::alloc_pdsch(slot_ue& ue, const prb_grant& dl_gr
   // Allocation Successful
 
   int                mcs   = ue.cfg->ue_cfg()->fixed_dl_mcs;
+  const static float max_R = 0.93;
   do {
     // Generate PDCCH
     pdcch_dl_t& pdcch = bwp_pdcch_slot.dl_pdcchs.back();
@@ -277,7 +278,7 @@ alloc_result bwp_slot_allocator::alloc_pdsch(slot_ue& ue, const prb_grant& dl_gr
     } else {
       srsran_assert(pdsch.sch.grant.tb[0].tbs == (int)ue.h_dl->tbs(), "The TBS did not remain constant in retx");
     }
-    if (bwp_pdsch_slot.pdschs.back().sch.grant.tb[0].R < 0.9 or mcs == 0) {
+    if (bwp_pdsch_slot.pdschs.back().sch.grant.tb[0].R < max_R or mcs == 0) {
       break;
     }
     // Decrease MCS if rate is too high