Reduced order H/sub /spl infin// filter design for discrete time-varying systems

This paper addresses the reduced-order H/sub /spl infin// filter design for linear time varying discrete-time systems in which all measurements are not noise-free. The proposed filter has a generalized Luenberger observer structure and its order can be as low as n-p, where n and p are the order of signal systems and the number of measurements, respectively. Several bounded real lemmas are developed and they are the only tools used to establish the reduced-order filter design in this paper.