Patent ID: 8437422

Claim:
A method of operating a mobile wireless communications device operable in a multiple input, multiple output (MIMO) space division multiple access (SDMA) communications mode, the method comprising: receiving of one or more signals from a base station at the mobile wireless communications device; determining a parameter related to a matrix H for a transmission channel from the base station to the mobile wireless communications device based at least in part on the one or more signals; determining (i) a receive beamforming vector v for the transmission channel and (ii) a codeword u, which is configured based at least in part on a product of the receive beamforming vector v and the matrix H for the transmission channel, by using a predetermined channel quality indicator (CQI) metric; and transmitting feedback information to the base station, the feedback information being representative of the codeword u, and configured for use in determining a transmit beamforming vector w for the mobile wireless communications device; wherein transmitting feedback information to the base station comprises: quantizing the codeword u into a feedback index value by matching the codeword u to at least one codeword of a pre-specified set of codewords in a codebook and retrieving an index value corresponding to the least one codeword; and transmitting the index value to the base station; and wherein the index value is selected to enable determination of the transmit beamforming vector w.