Patent ID: 7551682
Filing Date: 2009-06-23
Classification: H04B

Abstract:
1. A method comprising: at a first wireless communication device comprising a plurality of antennas, receiving uplink signals from a second wireless communication device that comprises a plurality of antennas and computing an uplink covariance matrix for an uplink channel between the first and second wireless communication devices from the received uplink signals; generating a plurality of candidate downlink beamforming weighting vectors from the uplink covariance matrix; and applying each of the candidate downlink beamforming weighting vectors to a corresponding downlink signal for transmission via the plurality of antennas of the first wireless communication device to the second wireless communication device such that multiple downlink signals are transmitted from the first wireless communication device to the second wireless communication device, each downlink signal with a different one of the plurality of candidate downlink beamforming weighting vectors; receiving at the first wireless communication device feedback messages from the second wireless communication device, wherein the feedback messages indicate reception quality of downlink signals received by the second wireless communication device from the first wireless communication device; selecting one or more of the candidate downlink beamforming weighting vectors for use in transmitting downlink signals from the first wireless communication device to the second wireless communication device based on the feedback messages received from the second wireless communication device.