A method of transmitting at least one data stream using superposition coding (SPC) in a wireless communication system is disclosed. More specifically, a method includes receiving feedback information from at least two access terminals (ATs), assigning 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 that of the second AT, and the second AT has a larger path loss than that of the first AT, channel coding the at least one inputted data stream by a channel coding scheme, modulating the at least one data stream using layered modulation scheme, allocating wireless resources to symbols of the first AT and the second AT, and transmitting the symbols to at least one of the first AT and the second AT according to the allocated wireless resources.