Patent Document ID: 20100026560
Application ID: 12183648
Patent Flag: 0

Claim One:
1. A method of antenna training for communicating in parallel multiple data streams using multi-beamforming between multiple-input multiple-output source and destination stations, comprising: estimating essentially optimal multi-beamforming vectors by multiple stages, with each stage including: (a) a source station obtaining a first transmit beamforming vector that is orthogonal to all, if any, prior transmit beamforming vectors from earlier stages; (b) the source station transmitting a training sequence modulated by the first transmit beamforming vector in the spatial domain; (c) a destination station receiving the training sequence modulated by the first transmit beamforming vector, and obtaining a first receive beamforming vector therefrom, such that the first receive beamforming vector is orthogonal to all, if any, prior receive beamforming vectors; (d) the source station transmitting a training sequence modulated by different transmit beamforming vectors; (e) the destination station receiving said training sequence modulated by different transmit beamforming vectors, and estimating a second transmit beamforming vector therefrom; and (f) the destination station feeding back the estimated second transmit beamforming vector to the source station, whereby the source station decodes/transforms back the fed back second transmit beamforming vector, wherein the second transmit beamforming vector is orthogonal to all, if any, prior transmit beamforming vectors in earlier stages.