The master-slave IIR filter adaptation algorithm

An adaptive IIR (infinite-impulse response) filtering algorithm is proposed which combines advantages of two error criteria. The algorithm is termed master-slave, as an auxiliary adaptive filter (the slave) is used to assist the adaptation of the main adaptive IIR filter. By using an additional FIR (finite-impulse-response) filter to minimize the output error criterion, an IIR filter can be adapted using the preferred equation error criterion, while noise present in the desired filter response will not lead to biased parameter values. This enables IIR filters to converge much more rapidly than is possible with output error minimization alone. A steepest-descent form of the algorithm has been derived which uses a simple test to guarantee stability of the adaptive filter.<>