Next Article in Journal
A Numerical Study on Influence of Temperature on Lubricant Film Characteristics of the Piston/Cylinder Interface in Axial Piston Pumps
Next Article in Special Issue
Risk Analysis of Lightning and Surge Protection Devices for Power Energy Structures
Previous Article in Journal
Selecting the Optimal Micro-Grid Planning Program Using a Novel Multi-Criteria Decision Making Model Based on Grey Cumulative Prospect Theory
Previous Article in Special Issue
A Dual-Voltage-Vector Model-Free Predictive Current Controller for Synchronous Reluctance Motor Drive Systems
Article Menu
Issue 7 (July) cover image

Export Article

Open AccessFeature PaperArticle
Energies 2018, 11(7), 1841;

Non-Distorted Optimization Spectrum Analysis

Department of Electrical Engineering, I-Shou University, Kaohsiung 840, Taiwan
Center of Teaching and Research, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan
Author to whom correspondence should be addressed.
Received: 8 June 2018 / Revised: 9 July 2018 / Accepted: 10 July 2018 / Published: 13 July 2018
(This article belongs to the Special Issue Selected Papers from the IEEE ICASI 2018)
Full-Text   |   PDF [12964 KB, uploaded 13 July 2018]   |  


The discrete Fourier transform is extensively applied in spectrum analysis. However, the sampled signal is random, and the discrete Fourier transform has its own specific limitations. Thus, errors will inevitably occur in time–frequency transformation work. The most common are the leakage effects of the spectrum that are caused from the scale of the spectrum not being able to match the characteristics of the signal. The optimal spectrum is proposed to overcome this defect by adjusting the frequency scale to fit signal characteristics. This includes three stages whereby frequency scale can match signal characteristics. Firstly, the signal parameters must be found. Secondly, the frequency scale can be determined from these signal parameters. Finally, the optimal spectrum can be realized using the adjustable spectrum with the new frequency scale. After processing the optimal spectrum, the leakage effects of the signal will be decreased to a minimum. This method preserves signal characteristics in the optimization process, which reaches the ideal of non-distortion. View Full-Text
Keywords: discrete Fourier transform; leakage effect; optimization discrete Fourier transform; leakage effect; optimization

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Wu, R.-C.; Huang, L.-J. Non-Distorted Optimization Spectrum Analysis. Energies 2018, 11, 1841.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Energies EISSN 1996-1073 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top