| Summary: | 碩士 === 國立臺灣海洋大學 === 電機工程學系 === 98 === Hilbert-Huang transformation (HHT) is one of the major time-frequency analysis methods and is suitable for the analysis of local time signals. In this article, we use HHT-based method to analysis the signal deemed of the spike wave. In addition, we describe the features of a spike wave recorded and a normal wave recorded for patients with epilepsy by using HHT analysis method. Under the no transmission error and the transmission error assumptions, we present the intrinsic mode functions (IMF), instantaneous frequencies (IF), Hilbert marginal frequencies, and Hilbert energy spectra for the spikes and the normal waves. Clear energy-frequency-time variations of the spikes and the normal waves with and without the transmission error are shown. There are five IMFs of a spike wave and a normal wave in the HHT analysis. Analysis results show that the ratio of the energy of a spike wave with the IMF3 and the total energy of a spike wave, the ratio of the energy of a spike wave with the IMF4 and the total energy of a spike wave, the ratio of the energy of a normal wave with the IMF4 and the total energy of a normal wave, the ratio of the energy of a normal wave with the IMF5 and the total energy of a normal wave are 34.55%, 33.73%, 43.25%, and 37.63%, respectively. The ratio of the energy of the IMF4 of a spike wave with (0.5Hz-4Hz) band and the total energy of the IMF4 of a spike is 98.4%. The ratio of the energy of the IMF4 of a normal wave with (0.5Hz-4Hz) band and the total energy of IMF4 of a spike is 82.2%. The mean IF of the IMF4 of a spike wave is smaller than the mean IF of the IMF4 of a normal wave. When the transmission bit error rate is , the performance of the spike-based HHT time-frequency characteristics is not affected.
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