This paper addresses the robust stability analysis problem of uncertain discrete-time linear systems subject to state delay, where the system state-space representation is allowed to be a rational function of the uncertain parameters. The stability conditions are obtained from Lyapunov-Krasovskii functionals with polynomial parameter dependence by means of nonlinear decompositions of rational vector functions. The proposed results are divided into delay dependent and delay independent, and they are expressed in terms of linear matrix inequalities (LMIs) constraints.
State delay; Uncertain Discrete-time Systems; Robustness; LMIs