Methods and devices for transmitting data in an Orthogonal Frequency-Division Multiple Access (OFDMA) wireless local area network, comprising: selecting, for a first resource unit assigned to the target station, a first modulation type; selecting, for a second resource unit assigned to the target station, a second modulation type different from the first modulation type; and modulating coded data and mapping the modulated data onto subcarriers associated with the assigned resource units based on the respective modulation types selected for each of the assigned resource units.