宽带信号的谱分析，信号分析主要包括时域分析和频域分析. 谱分析就是频域分析,谱就是指频谱,也就是在频域里分析信号有哪些规律,用的数学工具就是付立叶变换.-The spectral analysis of broadband signals

The Hilbert–Huang method is presented with modifications, for time-frequency analysis of distorted power quality signals. The empirical mode decomposition (EMD) is enhanced with masking signals based on fast Fourier transform (FFT), for separat