Simultaneous Variable Perturbation Method for the Active Noise Control System with a Wireless Error Microphone

This paper proposes the use of a wireless error microphone in active noise control (ANC) systems. There are several practical advantages of doing so. The target zone of quiet (ZoQ) is allowed to be reconfigured by simply moving the wireless error microphone. When the target ZoQ is large, many error microphones have to be placed. Using the wireless error microphone eases the deployment and maintenance work. However, the drawback of using wireless error microphones is due to the jitter effect of the wireless communication. The error signal samples arrive at the ANC controller at random time intervals, which sometimes are greater than the sampling interval. To solve this problem, this paper investigates the simultaneous perturbation (SP) method and proposes the simultaneous variable perturbation (SVP) method. Simulations of the ANC system with a wireless error microphone are carried out with acoustic paths measured in an actual setup. Simulation results demonstrate that when the SVP method reduces the broadband noise effectively even when the jitter effect is severe.