Robust Design of Linear MIMO Transceiver for Low SNR

In practical systems, the design of linear MIMO transceivers should be robust to partial or imperfect channel state information (CSI). This paper considers the case in which only the second-order statistics of the channel is known at the transmitter while the receiver has a perfect CSI. In such a case, it is possible to optimally design robust MIMO transceivers based on a general cost function covering several well known performance criteria. In particular, two families are considered in detail: Schur-convex and Schur-concave functions. Approximations are used in the low SNR regime to obtain simple optimization problems that can be readily solved. Numerical examples show substantial gains compared to other methods