A new framework for convergence analysis and algorithm development of adaptive IIR filters

A parameterization of an adaptive IIR filter´s poles is developed, based on balanced realization theory. From this we develop a local approximation of the actual adapted pole parameters, in which convergence speed is related to a certain eigenvalue spread. This, in turn, is shown to relate to the Hankel singular values of the system to be identified, as well as certain coefficient sensitivity functions of the adapted filter. Based on these properties, a new adaptive IIR algorithm is proposed. In order to achieve faster convergence, it combines an adaptive lattice with function approximation.