Patent ID: 8995342
Filing Date: 2015-03-31
Classification: H04W

Abstract:
1. An interference avoidance method performed by an Access Point (AP) in a WLAN system in an Overlapping Basic Service Set (OBSS) environment, the interference avoidance method comprising: receiving an interference avoidance request message from a first station (STA), the interference avoidance request message informing that frame transmission of the AP acts as interference with the first STA; transmitting an interference avoidance response message to the first STA in response to the interference avoidance request message; obtaining first channel information about a first channel between the first STA and the AP from the first STA which has received the interference avoidance response message, wherein the step of obtaining the first channel information includes: receiving a sounding data unit from the first STA; and estimating the channel using the sounding data unit, wherein the sounding data unit is a steered sounding data unit, and wherein the steered sounding data unit is precoded by the first STA using a receiving matrix obtained by the first STA by decomposing an estimate of a channel between the first STA and a third STA, the estimate of the channel between the first STA and the third STA being received by the first STA from the third STA via a second sounding data unit; determining a transmitting steering matrix based on the first channel information; and transmitting data to a second STA by performing beamforming according to the transmitting steering matrix.