A New Strategy for Online Secondary-Path Modeling of Narrowband Active Noise Control

Online secondary-path modeling (SPM) based on the use of random auxiliary noise is a very promising and attractive technique for implementing active noise control (ANC). In this paper, a new strategy is proposed for the online SPM of narrowband ANC (NANC). A bandpass filter bank consisting of IIR notch filters is applied to the residual noise to separate the uncancelled sinusoidal noise from other broadband noises due to the injected auxiliary noise and an additive noise. The extracted sinusoidal noise is used simultaneously to scale the auxiliary noise, to clean the desired signal for the SPM subsystem, and to update the controller. The benefits of this strategy are twofold. It can effectively reduce the contribution of injected auxiliary noise to the residual noise power. Meanwhile, it can also considerably raise the convergence rate of overall system as well as the accuracy of online SPM. Preliminary analysis is also provided to support the proposed strategy. Extensive simulations with synthetic/real secondary paths and noises are performed to demonstrate the superiority of the proposed SPM strategy over the conventional techniques.