Parallel multi-frequency narrowband active noise control systems

This paper analyzes and optimizes narrowband active noise control systems using multiple second-order adaptive filters. Theoretical analysis of the overall parallel structure is based on autocorrelation and cross-correlation matrices. Analytical result shows the use of single error signal to update all adaptive filters with different input signals will introduce extra tonal components in the residual noise. An optimized algorithm that uses bandpass filters to split the fullband error signal into multiple bandlimited subband error signals according to the frequencies of reference signals is developed to improve steady-state performance.