Patent ID: 7702029

Claim:
A method for precoding signals in a multiple input multiple output (MIMO) communication system, comprising: estimating channel state information for a transmission channel from a transmitting device to a first receiving device by receiving one or more signals; generating precoding information for the transmission channel by identifying a first precoding profile from a first codebook that corresponds to the channel state information, where the first codebook comprises a plurality of codewords, where each codeword comprises: a unitary precoding matrix portion, and a diagonal power control matrix portion to provide power control values for a plurality of streams, where a first power control value for beamforming specifies that full power is always applied to a predetermined one of the streams such that the unitary precoding matrix chosen for beamforming aligns the predetermined one of the streams to a dominant spatial channel of the plurality of streams, and where a second power control value for spatial multiplexing specifies that equal power is applied to each of the plurality of streams; and quantizing the precoding information corresponding to the first precoding profile into a precoding index.