PPDU receiving method and apparatus based on the MIMO technique in a WLAN system

A device for transmitting data in a wireless local area network comprising:

• a transceiver configured to transmit and receive radio signal;
• and
• a processor operatively coupled to the transceiver and configured to:
• instruct the transceiver to transmit a trigger frame to a plurality of receiving stations, wherein the trigger frame comprises:
• a bandwidth field indicating an operating bandwidth which is divided into a plurality of transmission channels;
• a plurality of identifiers, each of the plurality of identifiers identifying a respective one of the plurality of receiving stations that is requested to perform an uplink multi-user multiple input multiple output (MU-MIMO) transmission;
• and
• a plurality of channel fields, each of the plurality of channel fields indicating a transmission channel of the plurality of transmission channels that is assigned to a corresponding one of the plurality of receiving stations;
• instruct the transceiver to receive a plurality of data frames from the plurality of receiving stations, each of the plurality of data frames being received through a transmission channel assigned to a corresponding one of the plurality of receiving stations;
• and
• instruct the transceiver to transmit, to the plurality of receiving stations, a plurality of acknowledgement frames acknowledging a corresponding one of the plurality of data frames, each of the plurality of acknowledgment frames being transmitted through the transmission channel assigned to the corresponding one of the plurality of receiving stations,
• wherein a first time interval between the trigger frame and the plurality of data frames is equal to a second time interval between the plurality of data frames and the plurality of acknowledgment frames.