Disclosed according to one embodiment of the present invention is a method whereby a first station (STA) transmits signals using dual carrier modulation (DCM) in a wireless LAN system, comprising: modulating HE-SIG B field information and/or data field information on a wireless frame transmitted by the first STA and transmitting same to a second STA, wherein in the case of modulating the HE-SIG B field information and/or the data field information in a BPSK mode, if a random symbol C1 among symbols modulated in the BPSK mode is mapped to a subcarrier K, a symbol formed by rotating the phase of the symbol C1 is mapped to a subcarrier K+N/2 in a repeating manner, wherein N corresponds to the number of subcarriers of a resource unit for transmitting the HE-SIG B field information and the data field information and K is a random integer equal to or less than N/2.