Adaptive IIR filtering using cascade structures

This paper studies the use of cascade form filter structures for implementing adaptive IIR filters. An efficient scheme for the computation of the gradient is developed. This greatly simplifies the complexity of the adaptive algorithms for cascade implementation of adaptive IIR filters. Issues related to the convergence of the adaptive cascade filter, and computational complexity reduction via alternate mixed form implementations are explored. The application of the cascade IIR adaptive filter for enhancing narrowband/sinusoidal signals in noise is also considered. Simulation results are presented to support the observations.<>