A method for supporting Time-Quadrature Amplitude Modulation (TQAM) in a wireless communication system includes generating a transmission symbol identified by a combination of a QAM symbol and a position of a time resource to which the QAM symbol is mapped, shifting at least one QAM symbol among QAM symbols contained in the transmission symbols with respect to a time axis, and readjusting a constellation point of the QAM symbol on the basis of a shifting quantity. A method for operating a receive end comprises receiving a reception symbol identified by a combination of a QAM symbol and a position of a time resource to which the QAM symbol is mapped, restoring at least one QAM symbol shifted in a transmit end for uniformizing of the time-axis distribution of QAM symbols contained in the reception symbols, generating decoding metrics for the reception symbol, and performing decoding the reception symbol using the decoding metric.