Patent ID: 8483761
Filing Date: 2013-07-09
Classification: H04B

Abstract:
1. An apparatus comprising a communication device, the communication device comprising: a receiver configured to provide an observed beamformed channel matrix in response to receiving a first beamformed signal from a beamforming transmitter; a processor configured to perform a QR decomposition of the observed beamformed channel matrix to provide a unitary matrix, and to determine a goodness of criterion, wherein the processor is further configured to determine that the goodness criterion is not satisfied; and a beamformer configured to utilize a conjugate of the unitary matrix to transmit a beamformed reply signal to the transmitter if the goodness of criterion is not satisfied; until the goodness criterion is satisfied, the processor performing one or more successive iterations of the QR decomposition of the observed beamformed channel matrix is performed to provide an updated unitary matrix for each successive observed channel matrix so that for each iteration the beamformer utilizes an updated conjugate of the unitary matrix to transmit a beamformed reply signal to the beamforming transmitter for the one or more successive iterations, and the beamforming transmitter alternately uses identity matrixes for beamforming based on a QR decomposition of an observed current channel matrix of the beamformed reply signal transmitted to the beamforming transmitter.