diff --git a/openair2/LAYER2/MAC/eNB_scheduler.c b/openair2/LAYER2/MAC/eNB_scheduler.c index 4e063d2207..ea7b5a9a81 100644 --- a/openair2/LAYER2/MAC/eNB_scheduler.c +++ b/openair2/LAYER2/MAC/eNB_scheduler.c @@ -586,6 +586,23 @@ eNB_dlsch_ulsch_scheduler(module_id_t module_idP, memset(cc[CC_id].vrb_map_UL, 0, 100); cc[CC_id].mcch_active = 0; clear_nfapi_information(RC.mac[module_idP], CC_id, frameP, subframeP); + + /* hack: skip BCH RBs in subframe 0 for DL scheduling, + * because with high MCS we may exceed code rate 0.93 + * when using those RBs (36.213 7.1.7 says the UE may + * skip decoding if the code rate is higher than 0.93) + * TODO: remove this hack, deal with physical bits properly + * i.e. reduce MCS in the scheduler if code rate > 0.93 + */ + if (subframeP == 0) { + int i; + int bw = cc[CC_id].mib->message.dl_Bandwidth; + /* start and count defined for RBs: 6, 15, 25, 50, 75, 100 */ + int start[6] = { 0, 4, 9, 22, 34, 47 }; + int count[6] = { 6, 7, 7, 6, 7, 6 }; + for (i = 0; i < count[bw]; i++) + cc[CC_id].vrb_map[start[bw] + i] = 1; + } } /* Refresh UE list based on UEs dropped by PHY in previous subframe */