Analysis of Mode Mixing Phenomenon in the Empirical Mode Decomposition Method

Empirical mode decomposition (EMD) can adaptively separate the intrinsic oscillatory modes of signals into a finite number of intrinsic mode functions (IMFs). IMFs will lose their physical meaning when mode mixing phenomenon occurs. In this paper, we first analyze the relationship between mode mixing and intermittency in signals. We then introduce a new type of mode mixing which is not caused by intermittency in signals. Finally, we argue that the time-varying extrema sampling rate is the essential reason of mode mixing.