Quantized H∞ filter for discrete time-delay systems via small gain theorem

This paper is concerned with the quantized H_∞ filtering problem for discrete-time systems, which includes measurement quantization and time-varying delay. The quantized H_∞ filtering problem of systems with time-varying delays is transformed into the scaled small gain problem through a process two-term approximation. By using the Scaled Small Gain(SSG) Theorem and Lyapunov-Krasovskii functional(LKF) approach, sufficient conditions of the stability for the quantized filtering error system with a prescribed H_∞ performance level can be obtained. Then the corresponding quantized H_∞ filter can be designed to guarantee the asymptotic stability of the error system and also achieve the prescribed H_∞ disturbance attenuation level. A numerical example shows the validity of the designed filter.