Yang, Zhijing and Yang, Lihua and Qing, Chunmei and Huang, Daren (2008) A method to eliminate riding waves appearing in the empirical AM/FM demodulation. Digital Signal Processing, 18 (4). pp. 488-504. ISSN 1051-2004

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Abstract

Empirical mode decomposition can decompose a complicated signal into a sum of finite intrinsic mode functions whose instantaneous frequencies computed by the analytic signal method give a physically meaningful characterization of the signal. However, it is found that computing the instantaneous frequency of an intrinsic mode function through the Hilbert transform may produce some ridiculous results. Recently, an empirical AM/FM (amplitude and frequency modulation) demodulation for computing the instantaneous frequency of an intrinsic mode function has been proposed by Huang and his coworkers. This method totally eschews the Hilbert transform and can compute the instantaneous frequency of an intrinsic mode function very accurately. However, this paper will show that the empirical FM part extracted through the empirical AM/FM demodulation may contain riding waves and is no longer an intrinsic mode function. That will make the instantaneous frequency nonsensical. To overcome this drawback, an improved method, called riding wave turnover-empirical AM/FM demodulation, is proposed in this paper. Experiments show very positive results.

Item Type:	Article
Additional Information:	Empirical mode decomposition can decompose a complicated signal into a sum of finite intrinsic mode functions whose instantaneous frequencies computed by the analytic signal method give a physically meaningful characterization of the signal. However, it is found that computing the instantaneous frequency of an intrinsic mode function through the Hilbert transform may produce some ridiculous results. Recently, an empirical AM/FM (amplitude and frequency modulation) demodulation for computing the instantaneous frequency of an intrinsic mode function has been proposed by Huang and his coworkers. This method totally eschews the Hilbert transform and can compute the instantaneous frequency of an intrinsic mode function very accurately. However, this paper will show that the empirical FM part extracted through the empirical AM/FM demodulation may contain riding waves and is no longer an intrinsic mode function. That will make the instantaneous frequency nonsensical. To overcome this drawback, an improved method, called riding wave turnover-empirical AM/FM demodulation, is proposed in this paper. Experiments show very positive results.
Keywords:	Empirical mode decomposition (EMD), Intrinsic mode function (IMF), Instantaneous frequency (IF), Empirical AM/FM demodulation, Riding wave
Subjects:	G Mathematical and Computer Sciences > G120 Applied Mathematics
Divisions:	College of Sciences > Faculty of Science > Lincoln School of Engineering
Depositing User:	Zhijing Yang
Date Deposited:	13 Feb 2011 19:07
Last Modified:	13 Mar 2013 08:55
URI:	http://eprints.lincoln.ac.uk/id/eprint/4014

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