Frequency domain active noise control system using optimal step-size parameters

We propose a frequency domain active noise control system using optimal step-size parameters at each frequency. The proposed ANC system can converge faster than the conventional ANC system using the Filtered-x LMS algorithm with the optimal step-size parameter. Moreover, the proposed system can converge by setting the step-size parameters at unstable frequencies to 0 in the case where the phase error of the secondary path model does not satisfy the stable condition, whereas the conventional ANC system cannot converge in this case. In this paper, the theoretical equation of the optimal step-size parameters is derived by using available information during system operation. Next, we present the structure of the ANC system using the optimal step-size parameters obtained from the theoretical equation. Moreover, a control technique determining unstable frequencies is introduced. Finally, simulation results demonstrate the efficiency of the proposed ANC system