A multi-channel narrowband active noise control system with simultaneous online secondary- and feedback-path modeling

The secondary- and feedback-path (SP, FBP) compensation in active noise control (ANC) has been studied for decades. In this paper, a novel narrowband ANC (NANC) system having multiple reference channels is proposed. It is comprised of two subsystems, namely an online SP modeling (SPM) subsystem and an online FBP modeling (FBPM) subsystem. The two subsystems are updated simultaneously to effectively mitigate the target sinusoidal noise. The former subsystem aims at obtaining a good SP estimate for updating the ANC controller, while the latter one attempts to remove the FBP influence on the system performance. An auxiliary white Gaussian noise (AWGN) that is scaled by a nonlinear function of the residual noise is injected into the secondary source to perform both the SPM and FBPM. A cascaded adaptive IIR notch filter bank is placed in series with the controller to reduce the coupling effects between the FBPM subsystem and the controller, and at the same time to extract sinusoids that are fed to each subcontroller (magnitude and phase adjuster (MPA)). The FXLMS and LMS algorithms are applied to the controller, the SPM and the FBPM subsystems, respectively. Extensive simulations demonstrate the effectiveness of the proposed NANC system.