关键词: 经验模态分解, 模式混淆, 瞬时频率, 频域分辨率

Abstract:

The main task of Empirical Mode Decomposition (EMD) is to offer the monocomponents or narrow band signals prior to Hilbert transform. During the EMD , the frequency band of intrinsic mode function (IMF) is rather wide due to the mode mixing and the signal interaction. In order to solve this problem , the band width of IMF resulting from a single EMD is investigated , and the corresponding instantaneous frequency resolution is calculated ,
on the basis of which an improved signal masking method is proposed to narrow the frequency band of signal before the standard EMD. Experimental results show that the proposed method can not only overcome the mode mixing in EMD completely but also avoid the disadvantages caused by the signal interaction , thus effectively improving the frequency-domain resolution expressed by IF after the Hilbert transform of IMF.

Key words: Empirical Mode Decomposition, mode mixing, instantaneous frequency, spectrum resolution