In one embodiment, the assistance information reporter 824 transmits, via the transmitter 812, its own assistance information to the BS, regardless whether the UE 800 serves as a relay UE or a remote UE in the cellular network.

In another embodiment, the UE 800 serves as a remote UE. In this case, the assistance information reporter 824 transmits, via the transmitter 812, its own assistance information to a relay UE. The relay UE will either forward the assistance information to the BS or perform configuration and/or adjustment of MCS of the relay UE in sidelink communications.

In yet another embodiment, the UE 800 serves as a relay UE. In this case, the assistance information reporter 824 receives, via the receiver 814, assistance information of at least one remote UE that receives data in the sidelink communication from the UE 800. The assistance information reporter 824 may report the assistance information to the BS or send the assistance information to the MCS adapter 820 for determining or modifying an MCS to be used in sidelink communications based on the assistance information.

It can be understood that according to different embodiments, a UE may include only one of the category information reporter 822 and the assistance information reporter 824 for MCS adaptation.

The various modules discussed above are coupled together by a bus system 830. The bus system 830 can include a data bus and, for example, a power bus, a control signal bus, and/or a status signal bus in addition to the data bus. It is understood that the modules of the UE 800 can be operatively coupled to one another using any suitable techniques and mediums.