Adaptive Codebook Selection for Limited Feedback MIMO Beamforming Systems

A combined codebook for limited feedback multi-input multi-output (MIMO) beamforming system is proposed, where two grassmannian codebooks are combined together to make a set of new codebooks, and from which to choose the codebook for quantification. The codebook selection information is implied in the feedback codeword indexes, thus we can to switch the codebook adaptively. Simulation results show that this method can be used to any channel models, and at the same BER, this method can reduce the feedback rate compare to grassmannian codebooks in correlated channels.