Patent ID: 8379745

Claim:
A method of detecting variations in a forward wireless channel in a wireless communication system, the method comprising: monitoring a plurality of reverse channel estimates in a reverse wireless channel in the wireless communication system; estimating a Doppler spectrum of the reverse wireless channel from the plurality of reverse channel estimates, including measuring a Doppler spectrum of the reverse channel estimate based on i) a reverse channel estimate at a first time instant a first reverse link packet is received from the receiver on the reverse wireless channel after a beamformed packet was transmitted to the receiver on the forward channel, and ii) a reverse channel estimate at a second time instant a second reverse link packet is received from the receiver on the reverse wireless channel; estimating a Doppler spectrum of the forward wireless channel from the Doppler spectrum of the reverse wireless channel; initiating an update of a steering matrix, to be used for beamforming of transmissions sent via the forward wireless channel, if the Doppler spectrum of the forward wireless channel varies beyond a threshold.