A Technique for Active Noise Control Systems with Online Secondary Path Modeling Using Additive Noise Power Scheduling

This paper proposes a new method for online secondary path modeling (OSPM) in active noise control (ANC) systems. The proposed method comprises two adaptive filters: a noise control filter and an OSPM filter. The noise control filter is adapted by the FxLMS algorithm, and using the same error signal as used in the adaptation of the OSPM filter. The OSPM filter is adapted using a variable step size (VSS) LMS algorithm already proposed by authors. Furthermore, the OSPM filter is excited by an additive random noise with a variable power. Initially, when the disturbance signal is large, a small step size and large additive random noise are used in the OSPM filter. Later, when ANC system converges, step size is increased and the variance of the additive random noise is decreased. The computer simulations show that the proposed method gives best performance among the existing methods.