Method and device for preventing interference in overlapping service area

Patent metadata

Field	Value
Publication number	US-2016249366-A1
Application number	US-201415024765-A
Country	US
Kind code	A1
Filing date	Jun 19, 2014
Priority date	Oct 22, 2013
Publication date	Aug 25, 2016
Grant date	—

Abstract

A method and a device for preventing interference in an overlapping service area are disclosed. The method for preventing interference in an overlapping service area of a wireless LAN can comprise the steps of: receiving, by an interference AP, a beacon frame broadcasted by an AP, wherein the beacon frame includes an interference prevention information element; receiving, by the interference AP, a sounding PPDU indicated on the basis of the interference prevention information element from the AP; determining, by the interference AP, a transmission control matrix on the basis of the sounding PPDU; and transmitting, by the interference AP, data through a beam generated on the basis of the transmission control matrix.

First claim

What is claimed is:

1 . A method of preventing interference in an overlapping service area of a wireless local area network (WLAN), the method comprising:
receiving, by an interfering access point (AP), a beacon frame broadcasted by an AP, the beacon frame comprising an interference avoidance information element; receiving, by the interfering AP, a sounding physical layer convergence procedure (PLCP) protocol data unit (PPDU) indicated based on the interference avoidance information element from the AP; determining, by the interfering AP, a transmit steering matrix based on the sounding PPDU; and transmitting, by the interfering AP, data through a beam generated based on the transmit steering matrix.

2 . The method of claim 1 , wherein the interference avoidance information element indicates that transmission of the sounding PPDU is performed a short inter-frame symbol (SIFS) after transmission of the beacon frame.

3 . The method of claim 1 , wherein the transmit steering matrix is determined to reduce interference by the interfering AP in communication between the AP and a station (STA) associated with the AP based on channel state information on a channel between the interfering AP and the AP, and the channel state information comprises a beamforming feedback matrix for a plurality of subcarriers transmitting the sounding PPDU.

4 . The method of claim 1 , wherein the interfering AP is positioned in coverage of a first basic service set (BSS) comprising the AP, and the AP is positioned in coverage of a second BSS comprising the interfering AP.

5 . The method of claim 1 , wherein the sounding PPDU is a steered sounding PPDU, and the steered sounding PPDU is precoded based on a precoding matrix acquired based on a different sounding PPDU transmitted by an STA associated with the AP to the AP.

6 . An access point (AP) for preventing interference in an overlapping service area of a wireless local area network (WLAN), the AP comprising:
a radio frequency (RF) unit configured to transmit or receive a radio signal; and a processor selectively connected to the RF unit, wherein the processor receives a beacon frame broadcasted by another AP, the beacon frame comprising an interference avoidance information element, receives a sounding physical layer convergence procedure (PLCP) protocol data unit (PPDU) indicated based on the interference avoidance information element from the other AP; determines a transmit steering matrix based on the sounding PPDU, and transmits data through a beam generated based on the transmit steering matrix.

7 . The AP of claim 6 , wherein the interference avoidance information element indicates that transmission of the sounding PPDU is performed a short inter-frame symbol (SIFS) after transmission of the beacon frame.

8 . The AP of claim 6 , wherein the transmit steering matrix is determined to reduce interference by the AP in communication between the other AP and a station (STA) associated with the other AP based on channel state information on a channel between the AP and the other AP, and the channel state information comprises a beamforming feedback matrix for a plurality of subcarriers transmitting the sounding PPDU.

9 . The AP of claim 6 , wherein the AP is positioned in coverage of a first basic service set (BSS) comprising the other AP, and the other AP is positioned in coverage of a second BSS comprising the AP.

10 . The AP of claim 6 , wherein the sounding PPDU is a steered sounding PPDU, and the steered sounding PPDU is precoded based on a precoding matrix acquired based on a different sounding PPDU transmitted by an STA associated with the other AP to the other AP.

11 . A method of preventing interference in an overlapping service area of a wireless local area network (WLAN), the method comprising:
transmitting, by an interfering access point (AP), a beacon frame broadcasted to an AP, the beacon frame comprising an interference avoidance information element; transmitting, by the interfering AP, a sounding physical layer convergence procedure (PLCP) protocol data unit (PPDU) indicated based on the interference avoidance information element to the AP in a certain period of time after the beacon frame; receiving, by the interfering AP, channel state information on a channel determined by the AP based on the sounding PPDU; determining, by the interfering AP, a transmit steering matrix based on the channel state information; and transmitting, by the interfering AP, data through a beam generated based on the transmit steering matrix.

12 . The method of claim 11 , wherein the certain period of time is a short inter-frame symbol (SIFS),
the interference avoidance information element indicates that transmission of the sounding PPDU is performed the SIFS after transmission of the beacon frame, and the interfering AP is positioned in coverage of a first basic service set (BSS) comprising the AP, and the AP is positioned in coverage of a second BSS comprising the interfering AP.

13 . The method of claim 11 , wherein the sounding PPDU is a steered sounding PPDU, and the steered sounding PPDU is precoded based on a precoding matrix acquired based on a different sounding PPDU transmitted by an STA associated with the AP to the interfering AP.

Assignees

• Lg Electronics Inc

Inventors

• Seok Yongho

Classifications

• H04W72/541 Primary

  using the level of interference · CPC title

• H04W72/27

  between access points · CPC title

• H04B7/024 Primary

  Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems · CPC title

• H04W88/08

  Access point devices · CPC title

• H04W16/28

  using beam steering · CPC title