Virtual reference signals for active noise cancellation system.

Abstract

This paper proposes a method that provides a new set of linear fixed coefficients filters to define and synthesize a new set of reference signals that are fewer in number than the original set of reference signals. It also can be used as the reference signals for an active noise cancellation system. To optimize the performance of the active noise cancellation system, it is very important to find proper reference signals that are coherent with the target noise. In a case of active road noise cancellation in a vehicle cabin, for satisfying this particular requirement, many accelerometers are installed to detect vibration on the vehicle's suspension mechanism. In most cases, these reference signals contain information about fewer number of noise sources compared to the number of accelerometers. Proposing the linear filtering method that is based on Singular Value Decomposition (SVD) of the power spectrum matrix of the reference signals enables the synthesis of the virtual reference signals. After defining the frequency response functions of the filters, we design the ARMA direct form digital filters. After designing the fixed coefficients filters for the virtual reference signals, we evaluate the performance of the ANC system through experimental tests and its results by comparing the original reference signals and the virtual reference signals to confirm the proposed method.