DESIGN OF STABLE IIR FILTERS IN THE COMPLEX-DOMAIN BY AUTOMATIC DELAYSELECTION

A major problem encountered when designing infinite impulse response ( IIR) filters in the complex domain is to ensure that the filter is sta ble. Instability occurs frequently when the IIR filter approximates th e inverse of a nonminimum phase system, This is often the case for equ alization filters. Addition of delay to the target frequency response can result in a stable filter, However, to date, delay selection has b een a matter of trial and error. This correspondence presents an autom ated method for finding the delay.