光子多普勒测速系统信号解调方法比较

Comparison of Signal Demodulation Methods for Photon Doppler Velocimetry System

光子多普勒测速系统具有抗干扰能力强、测速范围大等优点,适用于信噪比低、信号质量差的测量场合。介绍光子多普勒测速系统的工作原理,详细阐述常用的四种信号解调方法——条纹法、相位解调法、短时傅里叶变换法、小波变换法的原理、特点和近几年的研究现状。利用上述四种信号解调方法对简谐振动调制的多普勒信号进行解调仿真,直观地展示不同信号解调方法的优缺点和适用性。实验结果表明,相位解调法最适合用于光子多普勒测速系统振动信号解调。最后讨论了采用递归希尔伯特变换的方法减小相位解调法的正交性误差的可行性,通过仿真实验验证了此方法的有效性。

The photon doppler velocimetry system has the advantages of strong anti-interference ability and wide range of velocity measure-ment.It is suitable for low signal-to-noise ratio and poor signal quality measurement occasions.The working principle of photon doppler velocime-try system is introduced.Four commonly used signal demodulation methods,fringe method,phase demodulation method,short-time Fourier transform method and wavelet transform method,are described in detail.The four signal demodulation methods mentioned above are used to de-modulate the doppler signal modulated by harmonic oscillation,and the advantages,disadvantages and applicability of different signal demodula-tion methods are shown intuitively.The experimental results show that the phase demodulation method is most suitable for demodulating the vibra-tion signal of photon doppler velocimetry system.Finally,the feasibility of using recursive Hilbert transform to reduce the orthogonality error of phase demodulation method is discussed,and the effectiveness of this method is verified by simulation experiments.