A robust dual-path DCD-RLS algorithm for stereophonic acoustic echo cancellation

The stereophonic systems create the illusion of audio directionality using independent channels with a standard configuration consisting of two microphones and two speakers. The basic associated mathematical model used to correct the acoustic echo that affects the system has two-input/ two-output real random variables with four adaptive filters. An important simplification to this scheme is the widely linear (WL) model which uses a single-input/ single-output system with complex valued random variables (CRVs) and only one adaptive filter. In order to demonstrate the functionality, the recursive least-squares (RLS) adaptive algorithm is used. The RLS is conveniently combined with the dichotomous coordinate descent (DCD) algorithm in order to greatly reduce the matrix inversion arithmetic complexity and an aggregate of two filters (with transfer logic - TL) is used to considerably improve performance in high disturbance situations such as double talk.