低信噪比正弦信号相位差测量算法对比研究

Comparative study of the phase difference measurement algorithms for low signal to noise ratio sine signal

相位差测量技术在许多领域有着广泛的应用,目前存在多种测量算法但并没有关于低信噪比正弦信号相位差测量的专题研究,针对这一问题研究了7种相位差测量算法的适用性和优缺点,其中包括相关分析法、傅里叶变换法、希尔伯特变换法、三参数法、数字锁相放大法、基于互相关的最小二乘法及正交延迟估计算法,详述了各算法的理论分析,并给出了具体算法在低信噪比条件下的MATLAB仿真结果,研究表明,三参数法、傅里叶变换法、数字锁相放大算法以及基于互相关的最小二乘法可以满足低至-20dB的正弦信号相位差的测量,测量精度达到5%以内,并且对于小相位差的测量有着良好的效果。

Phase difference measurement technology is widely used in many fields.There are many algorithms for phase difference measurement at present,but there is no study on low SNR signal.Aimed at this problem,the practicality and the advantages and disadvantages of seven algorithms were studied.Including correlation analysis,FFT,Hilbert transform,3PSF,digital lock-in amplifying,least square based cross-correlation and UQDE.And the MATLAB simulation results ofvarious algorithms under the condition of low signal to noise ratio are given.It shows that 3PSF,FFT,DLIA and the least square method based on cross-correlation can meet the measurement of weak sine signal phase difference of low to-20 dB under certain sampling condition,the precision is under five percent,and for small phase difference measurement effect is good.