基于LabVIEW的模拟鉴相器仿真实验研究

Research Based on LabVIEW Simulation Phase Discriminator Simulation Experiment

针对模拟鉴相器软件设计中采样率与信号频率的关系问题,文中利用LabVIEW建立了模拟鉴相器的时域模型与单边带傅里叶变换等软件VI,并进行了仿真实验研究。实验结果表明,模拟鉴相器的正弦模型只有满足输入信号采样率与反馈信号采样率相等的条件下才能正常运行;采样率FS与max[f_i,f_0]之比越大失真越小;傅里叶变换中正弦模型包含了f_i+f_0与f_i-f_0频率分量、相位模型含有f_i-f_0频率分量,但是幅值与F_S无关。

Concerning the relationship between sampling frequency and signal frequency in software design of simulation phase discriminator, the paper uses LabVIEW to set up software VI such as time domain model of simula- tion phase discriminator and single side band Fourier transform , and conducted simulation experiment as well. exper- imental results indicate： only when sinusoidal model of simulation phase discriminator meet the condition that sam- piing rate of input signals and feedback signals equal to each other, simulation phase discriminator can operate nor- mally. Higher ratio of sampling frequency Fs to max[fi ,f0 ] means lower levels of distortion. In Fourier transform, si- nusoidal model involves sum frequency and difference frequency components. Phase model involves differential fre- quency components. But amplitude and sampling frequency are not related.