LTE Resource Block allocation based on MCS

Question

I wish to know:: in case of LTE if a CC has multiple RBs, then can a UE be allocated RBs using different MCS at different TTI? Ex: if CC1 has 5RBs with expected CQI[2,3,1,2,3] , for this case whether all the RBs to be allocated to UE1 using same MCS OR at TTi 1 [2,2] be given at MCS2; at TTi2[3,3] given at MCS3 and at TTI 3[1] be given at MCS1. Is it allowed?. Assuming NO MIMO.

Answer 1

Yes, it is allowed. It is called adaptive modulation. There are precisely two kinds of modulation - adaptive and non-adaptive. For Downlink, it is adaptive depending on link adaptation. For uplink, it can be adaptive or non-adaptive. If DCI 0 is send along with HARQ NACK to UE from eNB, then it is adaptive modulation. In case there is no DCI 0 with HARQ NACK to UE, it assumes it to be non-adaptive modulation.