Recursive least-squares algorithms with good numerical stability for multichannel active noise control

Some recursive least-squares algorithms for multichannel active noise control have recently been introduced, including computationally efficient (i.e. “fast”) versions. However, these previously published algorithms suffer from numerical instability due to finite precision computations. In this paper, numerically robust recursive least-squares algorithms for multichannel active noise control systems are introduced, using QR decompositions and lattice structures. It is shown through simulations of broadband multichannel active noise control that the recursive least-squares algorithms introduced in this paper are indeed more numerically robust than the previously published algorithms, while keeping the same convergence behavior, and therefore they are more suitable for practical implementations.