DISCRETIZATION AND FIR FILTERING OF CONTINOUS LINEAR-SYSTEMS WITH INTERNAL AND EXTERNAL POINT DELAYS

A discrete quasi-autoregressive moving average (QARMA) model and an eq uivalent impulse response (IR) description are established for linear continuous systems with internal and external point delays which are d iscretized through a sampler and zero-order-hold device. The QARMA-mod el is proved to differ from the standard autoregressive moving average (ARMA) models because of its infinite input memory caused by the dela ys. Based on the IR-model, a finite impulse response (FIR)-filter is p roposed to approximate the input-output description under exponential stability of the unforced system. Its implementation is discussed by u sing fast filtering design tools.