基于信号延拓的采样信号频谱泄漏抑制

提出一种基于信号数据延拓的采样信号离散傅里叶变换频谱泄漏抑制方法,分析了经典谱估计方法中频谱泄漏产生的原因,得出含噪声周期信号的无泄漏条件,进而提出频谱泄漏抑制方法:对采样信号作周期估计和整数周期数据延拓处理,使DFT计算窗内信号的边界连续或近似连续,以达到抑制频谱泄漏的目的。对通信、电力系统中常出现的加性高斯白噪声恶化信号的仿真表明:该方法可以显著减少频谱能量泄漏,获得更高质量的频谱。

Restraining method of frequency spectrum leakage of sampled signals based on signal extension

A method of restraining DFT frequency spectrum leakage of sampled signals based on signal extension is proposed.The reason of frequency spectrum leakage of Fourier transform is analyzed,and the condition of analyzing periodical signal deteriorated by noise without spectrum leakage is deduced.The restraining method is:firstly,the period of the sampled signal is estimated,and then the signal is extended to an integer period sequence,which makes the data boundary in DFT computation window continuous,thus spectrum leakage can be restrained.Simulations of communication and power system signals deteriorated by additive white Gaussian noise show that the proposed method can decrease spectrum leakage a lot and obtain high-quality spectrum.