METHOD FOR PERFORMING CHANNEL SOUNDING IN WIRELESS LAN SYSTEM AND APPARATUS FOR SUPPORTING SAME

摘要

The present invention relates to a method of performing channel sounding in a wireless LAN system. The method includes transmitting a Null Data Packet Announcement (NDPA) frame for providing notice of an NDP to be transmitted, and transmitting the NDP and receiving a feedback frame from a station (STA). The feedback frame includes channel state information created on the basis of the NDP. The NDP includes a signal field and at least one long training field (LTF) for a multiple input multiple output channel. The signal field includes a repetitive instruction subfield. The repetitive instruction subfield provides instruction on whether orthogonal frequency division multiplexing (OFDM) symbol repetition is applied to the at least one LTF.

主权项

1. A method for performing channel sounding in a wireless LAN system, the method comprising the steps of:
transmitting a null data packet announcement (NDPA) frame to announce a transmission of a null data packet (NDP); transmitting the NDP; and receiving a feedback frame from a station (STA), wherein the feedback frame includes channel state information generated based on the NDP, the NDP includes at least one long training field (LTF) for a signal field and a multiple input multiple output (MIMO) channel, the signal field includes a repetition indication subfield, and the repetition indication subfield indicates whether orthogonal frequency division multiplexing (OFDM) symbol repetition is applied to the at least one LTF.