2012 Volume 33 Issue 6 Pages 339-347
We propose a two-channel adaptive algorithm efficiently utilizing independent components slightly involved in reference signals. In active noise control systems, the conventional methods of adding independent components to the reference signals or deliberately changing the correlation between the reference signals are inapplicable, because the reference signals are only detected by noise detection microphones. We have hence presented an adaptive algorithm that does not require the addition of the independent components or the deliberate change to the reference signals. However, this algorithm has three drawbacks. The first is that one of the convergence conditions is described by unmeasurable signals. The second is that pre-estimation of the reference signal power ratio is required. The third is that unknown acoustic paths cannot be identified when the reference signals have high cross-correlation between different sample times. In this work, we derive a new algorithm without the drawbacks and verify, using computer simulations, that the derived algorithm can successfully identify the unknown acoustic paths. The two-channel active noise control system using the simultaneous equations method is thereby expected to provide a high noise reduction effect.
