Abstract

This article deals with the control of a two-input two-output (TITO) discrete time LTI plant, where one control signal is to be sent through a transparent channel, and the remaining control signal has to be sent through a channel that presents signal-to-noise ratio (SNR) constraints. For this situation, we study three different control architectures: state feedback, output feedback, and output feedback enriched with feedback around the constrained channel. We explore how the stability, and the best achievable performance, depend on the location of the SNR constrained channel for each architecture. An interesting conclusion of this work is that the best channel choice, when stability is the only concern, may be inadequate when the focus is on performance. A numerical example is included to illustrate our results. © 2011 IFAC.