A novel adaptive time-frequency analysis method,LCD was proposed based on the study of ITD.By using the presented method,a complicated multi-component signal could be adaptively decomposed into a number of intrinsic scale components with physically meaningful instantaneous frequencies.Basic principle of LCD was described in detail after a brief introduction to ITD.To investigate stopping criteria for iterative process,standard deviation criterion was applied to LCD,which was introduced in empirical mode decomposition(EMD).Varying with the selected adaptive time-frequency analysis method,the threshold of standard deviation criterion had no adaptability.Given the drawback of standard deviation criterion,a new adaptive stopping criterion named extreme monotonicity criterion was proposed,which needed not to set any thresholds.Analysis results of signals demonstrate validity of the two stopping criteria.Moreover,extreme monotonicity criterion gains more applicability than standard deviation criterion and can be also directly applied to EMD.Additionally,computational efficiency of LCD and EMD was investigated,and the comparative analysis results show that LCD is superior to EMD in computational efficiency.
