THE GAMMA-FILTER - A NEW CLASS OF ADAPTIVE IIR FILTERS WITH RESTRICTED FEEDBACK

In this paper we introduce the generalized feedforward filter, a new class of adaptive filters that combines attractive properties of finite impulse response (FIR) filters with some of the power of infinite impulse response (IIR) filters. A particular case, the gamma filter, generalizes Widrow's adaptive transversal filter (adaline) to an infinite impulse response filter. Yet, the stability condition for the gamma filter is trivial, and least mean square (LMS) adaptation is of the same computational complexity as the conventional transversal filter structure. Preliminary results indicate that the gamma filter is more efficient than the adaptive transversal filter. We extend the Wiener-Hopf equation to the gamma filter and develop some analysis tools.