Blind adaptive preprocessing to multichannel feedforward active noise control system

The reference paths from original sources to reference sensors in multichannel feedforward active noise control (ANC) systems are often ignored by most ANC algorithms. Two blind preprocessing adaptive algorithms in time and frequency domain are proposed to deal with some more complicated applications, especially when the reference sensors cannot be located closely to noise sources or the noise sources are moving slowly. Blind preprocessing algorithm to the reference signals can improve the structure of the cross spectral density matrix of the inputs to the multichannel filtered-x least mean square (LMS) algorithm in the following stage, and faster convergence speed can be obtained. The computational complexity of two proposed algorithms is analysed and simulations with impulse responses measured in a real reverberant room is applied to verify the convergence performance of the proposed algorithm.