MULTI-INPUT MULTI-OUTPUT FAST QR DECOMPOSITION ALGORITHMFOR ACTIVE NOISE CONTROL (original) (raw)

Fast QR-decomposition based recursive least-squares (FQRD- RLS) algorithms are known for their good numerical properties and low computational complexity. However, they have so far not been used in active noise control (ANC) because the general implementa- tion would require multiple-input multiple-output (MIMO) FQRD- RLS algorithms, which are currently not available in the technical literature. Another reason is the lack of an explicit weight vector update equation in the FQRD-RLS algorithms, which prevents their use in structures where a copy of the coefficients is filtering a dif- ferent input sequence than that of the adaptive filter, e.g., the modi- fied filtered-x ANC (MFX-ANC) structure. In this paper, we der ive a MIMO-FQRD-RLS algorithm based on backward prediction er- ror updates. The proposed algorithm is applied to a multichannel MFX-ANC structure. We show how to avoid the explicit use of the weight vector in the MFX-ANC structure by reproducing the filtered-x signal fro...