Echo cancellation by global optimization of Kautz filters using an information theoretic criterion

In practical settings, the echo cancellation problem generally requires the adaptation of an IIR filter using some optimality criterion. This brings two problems: direct adaptation of numerator and denominator polynomial coefficients of IIR filters might result in unstable systems and/or the optimization might result in a suboptimal local minimum of the criterion. These two issues are addressed in this paper. To resolve the first problem, orthogonal Kautz filters are utilized for their stability is easily controlled through the pole locations. The second problem is addressed by employing an information theoretic optimality criterion, which has a parameter that is annealed to ensure global optimization.