METHOD AND DEVICE FOR PERFORMING SOUNDING PROCEDURE IN WIRELESS LAN SYSTEM

Disclosed are a method and a device for a sounding procedure related to an aggregated-physical layer protocol data unit (A-PPDU) support in a WLAN system. A method for performing a sounding procedure by a first station (STA) in a wireless LAN system comprises the steps of: receiving at least one null data PPDU (NDP) announcement frame from a second STA on a first frequency unit associated with a first type PPDU format and a second frequency unit associated with a second type PPDU format; receiving at least one NDP from the second STA on the first frequency unit and the second frequency unit; receiving at least one trigger frame from the second STA on the first frequency unit and the second frequency unit; and transmitting a feedback frame for at least one of the first frequency unit and the second frequency unit to the second STA, wherein the at least one NDP may be received from the second STA on the basis of a first type of training sequence and a second type of training sequence.