Disclosed is a method for a station (STA) device transmitting data in a wireless local area network (WLAN) system. The method for transmitting data, according to one embodiment of the present invention, comprises the steps of: FEC encoding transmission data; constellation mapping the transmission data; inserting a pilot tone in the transmission data; performing Inverse Discrete Fourier Transform (IDFT) on the transmission data; and upconverting the transmission data and transmitting a transmission signal, wherein, if an Orthogonal Frequency Division Multiple Access (OFDMA) scheme is applied to the transmission signal, the transmission signal comprises at least one tone unit which is the unit of subcarrier allocation of the OFDMA scheme.