On stabilizability of MIMO systems over parallel noisy channels

In this paper we study the mean square stabilizability of MIMO discrete-time linear time-invariant plants over parallel additive white noise channels. We also consider a basic linear encoder-decoder scheme based on the design of a diagonal scaling matrix. We analyse the case of non minimum phase plants in an output feedback control setting. We obtain necessary and sufficient conditions for mean square stabilization when each SISO branch of the channel is subject to an individual signal-to-noise ratio constraint. We characterize a region where the set of constraints are compatible with mean square stability.