An alternative envelope approach for empirical mode decomposition

The paper proposes an alternative envelope approach for empirical mode decomposition. Different from the existing envelope interpolation in the literature available, the new envelope has a simple analytical expression, by which the variations of the extrema in the iterative procedure are investigated in detail to reveal the nature of the sifting process. A comparison of the proposed envelope with the traditional cubic spline interpolation is made in the numerical simulation under a two-tone signal model, which shows that the proposed envelope approach has the fast convergence rate and the higher separation degree in the two-tone signal decomposition.