Patent ID: 8626177

Claim:
A method of transmitting at least one data stream using superposition coding (SPC) in a wireless communication system, the method comprising: receiving feedback information from at least two access terminals (ATs); assigning each of the at least two ATs as a first AT or a second AT based on the feedback information, wherein the first AT has a smaller path loss than the second AT; channel coding the at least one data stream by a channel coding scheme; modulating the at least one data stream using a layered modulation scheme; allocating wireless resources to symbols of the first AT and the second AT; and transmitting the symbols to at least the first AT or the second AT according to the allocated wireless resources, wherein the layered modulation scheme includes an inner layer and an outer layer, wherein at least one signal modulation constellation of the outer layer is rotated, wherein the first AT and the second AT are indicated by a control channel that is used to carry control information to the at least two ATs, wherein the control information includes a field for indicating a layer number of the layered modulation scheme and a field for indicating power level bits, the layer number corresponding to the inner layer or the outer layer, wherein the layer number for the first AT is different from the layer number for the second AT, wherein a default transmit power level for the first AT and a default transmit power level for the second AT are indicated by the layer number for the first AT and the layer number for the second AT, respectively, and wherein the power level bits indicate a finer quantization level in relation to the default transmit power level for the first AT and the default transmit power level for the second AT.