用DFT分析正弦信号频谱时应注意的几个问题

Several Problems in Analyzing Sine Signal's Spectrum by DFT

从 DFT谱失真原因出发 ,分析了信号加窗和 DFT频域采样点数对 DFT谱的影响 ,指出了决定 DFT谱分辨率的主要是信号长度 ,即窗长度 ;在窗长度一定的情况下 ,窗类型也有影响 .而 DFT变换点数则决定 DFT谱与信号的

The cause of DFT-spectrum distortion and the effects of windowing signal in time domain and sampling DFT-spectrum in frequency domain on DFT-spectrum are analyzed. It is pointed out that the resolution of DFT-spectrum mainly depends on the length of signal or window, and when the length of window is given, it depends on the type of window. On the other hand, the number of DFT decides the degree of DFT-spectrum approximating to its DTFT-spectrum.