A framework for discrete-time models of continuous-time systems

This paper shows that the analysis and the design of discrete-time models of continuous-time systems can be carried out within a single framework. Briefly, all classes of discrete-time models, namely the invariant models, the mapping models and the matched pole-zero models, are shown to incorporate the common structure of a hold followed by a continuous-time system and the ideal sampler. This interpretation of discrete-time models of continuous-time systems facilitates the understanding of the differences and similarities among the various discrete-time models. A numerical example illustrates the concepts involved.