A method of operating a wireless local area network (WLAN) station. The WLAN station receives at least one desired signal and at least one interference signal from an access point (AP) capable of simultaneously transmitting desired signals to multiple WLAN stations. The method includes estimating a channel and generating a channel matrix estimated based on the estimated channel, separating a channel matrix of the desired signal and a channel matrix of the interference signal from the estimated channel matrix, generating the matrix of a virtual channel by combining the separated channel matrixes, and executing a sphere decoding (SD) algorithm using the matrix of the virtual channel.Or, separating a desired signal and an interference signal from the stream signal based on the analysis result, ascertaining a modulation scheme of the interference signal, and setting the ascertained modulation scheme of the interference signal as decreased lattice points.