An order of the field constructing the format of the PPDU disclosed in the upper portion of FIG. 14 may be changed. For example, as disclosed in a middle portion of FIG. 14, an HE-SIG B 1415 of an HE part may be located immediately next to an HE-SIG A 1405. The STA may perform decoding on the HE-SIG 1405 and up to the HE-SIG B 1415, may receive necessary control information, and may configure an NAV. Likewise, a size of IFFT applied to an HE-STF 1425 and a field next to the HE-STF 1425 may be different from a size of IFFT applied to a field prior to the HE-STF 1425.

The STA may receive the HE-SIG A 1405 and the RE-SIG B 1415. If it is instructed to receive the downlink PPDU by the STA identifier field of the HE-SIG A 1405, the STA may perform decoding on the downlink PPDU starting from the HE-STF 1425 by changing the FFT size. On the contrary, the STA may receive the HE-SIG A 1405, and if it is not instructed to receive the downlink PPDU on the basis of the HE-SIG A 1405, may configure the NAV.

Referring to a lower portion of FIG. 14, a downlink PPDU format for DL MU transmission is disclosed. According to an embodiment of the present invention, an AP may transmit a downlink frame or a downlink PPDU to a plurality of STAs by using a PPDU format for DL MU transmission. A plurality of downlink PPDUs may be transmitted respectively to the plurality of STAs through different transmission resources (frequency resources or spatial streams). For example, the AP may transmit downlink data for a TPC STA to the TPC STA through a TPC STA channel on the basis of a PPDU format for DL MU transmission, and may transmit downlink data for a non-TPC STA through a non-TPC STA channel.