Patent attributes
Disclosed is a wireless station having a receiver and a network allocation vector associated with each of a plurality of directional antennas. The receivers concurrently listen for frames from remote stations. When any receiver detects a frame from a remote station, the receiver activates its associated NAV. The station has one or more transmitters that can transmit using the antennas. While transmitting a signal using an antenna, the receivers associated with any non-transmitting antennas continue to listen for signals from remote stations. The station cancels any signals from the transmitting antenna received by the non-transmitting antennas. To perform the cancellation, the station performs a self-calibration procedure. The station can self-calibrate by either silencing neighboring stations or by inserting null tones into a transmitted calibration signal.