Stable accelerated adaptive DOA tracking algorithm

This paper is concerned with accelerated adaptive tracking algorithms for DOA estimation. New accelerated LMS and RLS type of adaptive algorithms are given from a standpoint that any parameter changes can be approximately expressed by a finite degree of polynomial function of time. The proposed algorithm involves a higher-order dynamics as an internal model in the adaptation loop. A sufficient condition for assuring stability of the accelerated adaptive algorithm is clarified based on the small gain and passivity theorems. The adaptive DOA tracking of rapidly moving sources can be attained and its effectiveness is examined in numerical simulations and experiments.