A sampling limit for the empirical mode decomposition

The aim of this paper is to investigate the effect of sampling on the empirical mode decomposition (EMD). To this end, an experiment utilising linear frequency modulated (LFM) signals was used to simulate different sampling rates. This experiment showed that as the frequency content of the signal (fc) approached the sampling frequency (fs) the EMD performed poorly due to poor amplitude resolution. This led to a definition of a sampling limit that was 5 times the Nyqvist rate (fs/10) to improve the performance of the EMD. Comparative simulation with this sampling limit was conducted on a simulated and a real world signal. The results exhibited significant improvement in intrinsic mode function (IMF) orthogonality, the distribution of IMF energy and IMF coherence