Two new criteria for the realization of interfered digital filters utilizing saturation overflow nonlinearity

In this paper, an input-to-state stability (ISS) approach is used to derive two new criteria for the realization of fixed-point state-space and direct-form digital filters with saturation overflow nonlinearity and external interference via augmented Lyapunov functions. The two proposed realization criteria ensure ISS for external interference. Moreover, these criteria guarantee asymptotic stability without external interference. They take the form of linear matrix inequality (LMI) and, hence, are computationally tractable. Illustrative examples demonstrate the effectiveness of the two proposed criteria.