Precoding of orthogonal space-time block codes over correlated Ricean MIMO channels

A precoder is designed for orthogonal space-time block codes (OSTBCs) for arbitrarily correlated Ricean multiple-input multiple-output (MIMO) channels. Unlike previous works, the precoder can be designed to minimize the exact symbol error rate (SER) as function of both a) the joint transmit-receive channel correlation coefficients, and b) the MIMO Rice component, which are fed back to the transmitter. Importantly, the covariance may or may not follow the so-called Kronecker structure. Exact SER expressions are given for multi-level PAM, PSK, and QAM signaling. Several properties of the minimum exact precoder are provided. An iterative numerical optimization algorithm is proposed for finding the exact minimum SER precoder under a power constraint.