1. An apparatus of a user equipment (UE) operable to report channel state information (CSI) for multi-user superposition transmissions (MUST), the apparatus comprising one or more processors and memory configured to:process a plurality of power offset parameters, that are received from an eNodeB, for the MUST;
perform a downlink channel measurement at the UE;
scale the downlink channel measurement using at least one of the plurality of power offset parameters to form one or more scaled downlink channel measurements;
calculate CQI values for the one or more scaled downlink channel measurements;
process, for transmission to the eNodeB, the CQI values for the one or more scaled downlink channel measurements to enable the UE to receive data on a physical downlink shared channel (PDSCH) using multi-user superposition transmission; and
differentially encode the CQI values relative to a reference CQI value for transmitting in the CSI report, wherein the reference CQI value corresponds to one of the plurality of power offset parameters that is defined as equal to one (1), corresponding to a single-user transmission without the MUST.