IIR Filter Banks and Wavelets

Abstract

In digital filtering applications, it is known that Infinite-duration Impulse Response (IIR) filters [108], [372], [418], [26] provide a computational advantage over Finite-duration Impulse Response (FIR) filters that are designed to meet the same magnitude specifications. In the early work on multirate digital signal processing, this advantage of IIR filters did not carry over to their use in sampling rate conversions. The initial disadvantage arose from the fact that a conventional approach to IIR filter design and realization does not allow the exploitation of rate conversion in reducing the computational burden. However, a different approach, based on the use of a polyphase structure, provides a powerful framework that proves to be common to a low-complexity implementation of both IIR and FIR filters for rate conversion. In this chapter we examine the properties and design of IIR filter banks for one-dimensional and two-dimensional signals.