Differential Rotation Feedback MIMO System for Temporally Correlated Channels

In fading channels, multiple-input multiple-output (MIMO) wireless systems make use of the spatial dimension of the channel to provide considerable capacity gain even when only partial channel state information (CSI) is available to the transmitter. A limited feedback linear preceding technique is proposed for temporally correlated MIMO channels where the receiver has perfect channel knowledge but the transmitter only receives quantized information regarding the channel instantiation. For this set-up, we first analyze capacity performance of a general rotation based limited feedback MIMO system in a Rayleigh flat fading channel. It can be shown that the minimum distance of the rotation codebook is related to the capacity performance of the system. Then, we present a framework for rotation based differential feedback by constructing the rotation codebook to adapt to the temporal correlation structure. Monte Carlo simulation results are presented to show the capacity performance of the proposed codebook design.