Patent ID: 7336727
Filing Date: 2008-02-26
Classification: H04B

Abstract:
1. A method for use in communication systems for transmitting signals from a transmitter having t transmit antennas and a receiver having r receive antennas by forming beams of electromagnetic radiation used to transmit signals from the transmitter to the receiver, the method comprising: transmitting a test signal from the transmitter to the receiver; computing a channel matrix by observing the effect of transmission on the test signal; selecting at least one eigenvector of the channel matrix, to achieve a desired performance level; selecting a beamforming vector from at least one codebook of predetermined beamforming vectors wherein the selected beamforming vector best approximates the at least one eigenvector; transmitting information identifying the selected beamforming vector from the receiver to the transmitter; and using the selected beamforming vector to transmit a signal from the transmitter to the receiver so that the desired performance level is achieved.