Method and device for transmitting feedback frame in wide band in wireless LAN system

A receiving station (STA) in a wireless local area network (WLAN) system, the receiving STA comprising:

• a memory;
• a transceiver;
• and
• a processor being operatively connected to the memory and the transceiver,
• wherein the processor is configured to:
• receive a Null Data Packet Announcement (NDPA) frame from a transmitting STA,
• receive a Null Data Packet (NDP) frame from the transmitting STA, and
• transmit a feedback frame to the transmitting STA based on the NDP frame,
• wherein the feedback frame includes information on a feedback subcarrier for a wideband,
• wherein, when the wideband is a contiguous 320 MHz band and a grouping value is equal to Ng, indexes of the feedback subcarrier are set to [−2036:Ng:−1540], [−1532:Ng:−1036], [−1012:Ng:−516], [−508:Ng:−12], [12:Ng:508], [516:Ng:1012], [1036:Ng:1532], and [1540:Ng:2036], and
• wherein [A:Ng:B] indicates that indexes of the feedback subcarrier are set from A to B at a spacing of Ng.

A method in a wireless local area network (WLAN) system, the method comprising:

• transmitting, by a transmitting station (STA), a Null Data Packet Announcement (NDPA) frame to a receiving STA;
• transmitting, by the transmitting STA, a Null Data Packet (NDP) frame to the receiving STA;
• and
• receiving, by the transmitting STA, a feedback frame from the receiving STA based on the NDP frame,
• wherein the feedback frame includes information on a feedback subcarrier for a wideband,
• wherein, when the wideband is a contiguous 320 MHz band and a grouping value is equal to Ng, indexes of the feedback subcarrier are set to [−2036:Ng:−1540], [−1532:Ng:−1036], [−1012:Ng:−516], [−508:Ng:−12], [12:Ng:508], [516:Ng:1012], [1036:Ng:1532], and [1540:Ng:2036], and
• wherein [A:Ng:B] indicates that indexes of the feedback subcarrier are set from A to B at a spacing of Ng.