Patent ID: 8189714

Claim:
A method for providing feedback to a multiple-input multiple-output, MIMO, transmitter from a MIMO receiver, which has a codebook comprising codebook codewords, codeword indices corresponding to the codebook codewords, and a codeword subset associated with each of a plurality of the codebook codewords, wherein each codeword subset comprises a subset of codebook codewords that best substantially correlate with the codebook codeword associated with the codeword subset and subset indices corresponding to the subset of codebook codewords of the codeword subset, comprising: selecting a first codeword from the codebook codewords based on first channel information at a first time; determining second channel information for a MIMO channel at a subsequent time; selecting a subset codeword from the subset of codebook codewords, which corresponds to the first codeword, based on the second channel information; and transmitting a subset index for the subset codeword to the MIMO transmitter.