Minimization of the Maximum Error between the Steady State and Transient Frequency Responses of IIR Filters using Initialization

When processing a limited number of samples, digital infinite impulse response (IIR) filters designed for steady state operation suffer from the transient effect. Their performance, however, can be improved by using initialization techniques. This paper presents a new method for designing IIR filters to process a limited number of samples. The equivalent FIR filter for an IIR filter with multiple-frequency initializations is used in the design method. It is based on the minimization of the maximum error between the steady state and the transient frequency responses. Filters designed using this method are shown to offer better transient frequency responses when compared to conventional steady state filters with and without initialization.