Robust processing of heavy tails signals-comparison of approaches

This paper deals with robust estimation of AR parameters. We compare the performance of the LMS algorithm to the performance of two robust, adaptive algorithms: the LMAD algorithm of Shao and Nikias (1993) in which the error signal in the LMS algorithm is hard-limited before used to control the weights, and the LLMS algorithm in which the input process is soft-limited before the LMS algorithm is applied. The comparison is done in terms of the rate of convergence and the stability (steady state variance). We show that with a proper choice of the limiting level, the LLMS algorithm outperforms the LMAD algorithms when applied to symmetric, /spl alpha/ stable processes of 1/spl les//spl alpha//spl les/2.