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Title: Time-frequency analysis of non-stationary fusion plasma signals using an improved Hilbert-Huang transform

An improved Hilbert-Huang transform method is developed to the time-frequency analysis of non-stationary signals in tokamak plasmas. Maximal overlap discrete wavelet packet transform rather than wavelet packet transform is proposed as a preprocessor to decompose a signal into various narrow-band components. Then, a correlation coefficient based selection method is utilized to eliminate the irrelevant intrinsic mode functions obtained from empirical mode decomposition of those narrow-band components. Subsequently, a time varying vector autoregressive moving average model instead of Hilbert spectral analysis is performed to compute the Hilbert spectrum, i.e., a three-dimensional time-frequency distribution of the signal. The feasibility and effectiveness of the improved Hilbert-Huang transform method is demonstrated by analyzing a non-stationary simulated signal and actual experimental signals in fusion plasmas.
Authors:
; ; ; ;  [1]
  1. Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)
Publication Date:
OSTI Identifier:
22308675
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 85; Journal Issue: 7; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; FREQUENCY ANALYSIS; OSCILLATION MODES; PLASMA; REGRESSION ANALYSIS; SIGNALS; SIMULATION; SPECTRA; THREE-DIMENSIONAL CALCULATIONS; TIME DEPENDENCE; TOKAMAK DEVICES