A New Method For Active Noise Control Systems With Online Acoustic-Feedback-Path Modeling

This paper proposes a new method for online modeling of the acoustic feedback path in active noise control (ANC) systems. The proposed method comprises three adaptive filters: 1) the FxLMS algorithm based noise control filter, 2) a variable step size (VSS) LMS algorithm based feedback path modeling (FBPM) filter, and 3) LMS algorithm based adaptive noise cancellation (ADNC) filter. The ADNC filter removes the disturbance from the desired response of FBPM filter. The disturbance signal in FBPM filter is thus decreasing in nature, (ideally) converging to zero. This gives basic idea for the VSS LMS algorithm for FBPM filter: a small step size is used initially and later its value is increased accordingly. The computer simulations show that the proposed method can reduce FBPM error at a faster convergence rate than the existing methods