Feedback control over packet dropping network links

This paper studies stabilization schemes for a discrete-time control systems in which the feedback loop includes a network link that may suffer packet drops. We model the packet dropping network link as an erasure channel and study state/output feedback stabilization schemes for linear systems of arbitrary dimension. We use the mean square deviation of the system state from zero (MSDZ) as our measure of performance and discuss how to obtain the gain matrix that asymptotically minimizes this quantity. To evaluate the potential of this control scheme, we then focus on the scalar case and compare it against an alternative control scheme that first uses Kalman filtering (with intermittent observations) to estimate the system state and then applies state feedback based on this state estimate. We provide both analytical and empirical comparisons and conclude that, under certain conditions, the two control schemes can have comparable performance; however, the proposed (state or output) feedback strategy is considerably simpler to implement.