Remote robust state estimation for nonlinear systems

This paper addresses the problem of robust remote state estimation for uncertain nonlinear discrete-time systems when sensor data are transmitted through a digital communication channel of finite bit-rate capacity. The goal is to determine the minimal channel rate required to guarantee a prescribed estimation accuracy in the presence of bounded model uncertainty. We derive an explicit, tractable lower bound on the channel bit rate that ensures this accuracy for any admissible uncertainty level. The bound highlights the fundamental role of the accuracy-to-uncertainty ratio in remote estimation. The analysis relies on a quadratic dissipation inequality describing system uncertainty within the framework of incremental input-to-state stability, leading to a constructive Lyapunov-based characterization. The proposed conditions admit a closed-form analytical expression for a class of systems, including the uncertain Lozi map, which serves as an illustrative example.