低频电磁信号的频率细化技术

Frequency Refining Technology of Low Frequency Electromagnetic Signals

在低频电磁信号中,为了得到某一个窄带内频谱的精细结构,提高频谱的频率分辨率,满足良好的实时性要求,文中提出了基于快速傅里叶变换算法的频率细化技术。通过复调制频率细化,将某一局部频谱放大,以便对低频电磁信号的频谱进行快速、准确的分析。利用复调制频率细化方法,对低频电磁信号进行Matlab仿真,其仿真结果表明,该方法比线性调频Z变换算法更有效、可行。

In the low frequency electromagnetic signal,in order to get the fine structure of a certain spectrum within the narrowband,improve the frequency resolution of spectrum,and meet the requirement of good real-timeness,this paper puts forward the frequency refining technology based on the fast Fourier transform algorithm.Through polyphonic system frequency refinement,we amplify a local spectrum to facilitate fast and accurate analysis for the low frequency electromagnetic signal spectrum.Matlab is used for simulation of the low frequency electromagnetic signal by the method of polyphonic system frequency refinement.The simulation results show that this method is more effective and feasible than the Chirp Z transformation algorithm.