Optimum MIMO precoder designs for Ricean fading channels

We consider the problem of space-time block code (STBC) design for Ricean fading channels in a multiple-input multiple-output (MIMO) communication system equipped with a linear minimum mean square error (MMSE) receiver. Two criteria, i.e., ergodic channel capacity and mean square error (MSE) are used for the design. Due to the complexity of the mathematics involved, no general solution has yet been proposed for a Ricean channel with arbitrary mean. In this paper, we present the necessary and sufficient conditions for the design of the optimal precoder applicable to any channel condition and any range of signal-to-noise ratio (SNR). Simulations verify that the performance of the MIMO system using the optimum precoder is indeed superior in performance.