中国激光, 2017, 44 (12): 1210002, 网络出版: 2017-12-11
相位敏感光时域反射系统数字正交解调算法分析及改进研究
Analysis and Improvement for Digital Quadrature Demodulation Algorithm on Phase-Sensitive Optical Time-Domain Reflectometric System
光纤光学 光纤传感 相位敏感光时域反射系统 数字正交解调 数字滤波器 空间分辨率 fiber optics fiber sensor phase sensitive optical time domain reflectometer digital quadrature demodulation digital filter spatial resolution
摘要
对相位敏感光时域反射系统数字正交解调算法进行了研究。分析了正交解调算法中数字滤波器群延时对系统定位精度的影响, 提出采用重定位方法矫正定位误差; 同时, 研究了系统空间分辨率受正交解调算法中数字滤波器的影响, 并通过仿真和实验,验证并分析了上述问题。结果表明, 重定位方法可消除正交解调算法中数字滤波器造成的定位误差, 系统空间分辨率由系统结构与数字滤波器共同决定, 且由数字滤波器决定的空间分辨率随数字滤波器阶数的增加而增加。实验中解调选择112阶滤波器较佳。
Abstract
The digital quadrature demodulation algorithm of phase sensitive optical time domain reflectometer is investigated. The influence of the group delay of the digital filter in quadrature demodulation algorithm on the positioning accuracy is analyzed, and the relocation method is proposed to correct the positioning error. Meanwhile, the influences of the digital filter in the quadrature demodulation algorithm on the spatial resolution of the system is simulated and experimented. The results show that the relocation method can eliminate the positioning error caused by the digital filter in the quadrature demodulation algorithm. The spatial resolution of the system is determined by the system structure and the digital filter, and the spatial resolution of the digital filter improves with the increase of the order of the digital filter. In this experiment, the demodulation is appropriate to select 112 order filter.
王旭, 刘珉含, 于淼, 常天英, 崔洪亮, 罗政纯, 付群健, 白杨. 相位敏感光时域反射系统数字正交解调算法分析及改进研究[J]. 中国激光, 2017, 44(12): 1210002. Wang Xu, Liu Minhan, Yu Miao, Chang Tianying, Cui Hongliang, Luo Zhengchun, Fu Qunjian, Bai Yang. Analysis and Improvement for Digital Quadrature Demodulation Algorithm on Phase-Sensitive Optical Time-Domain Reflectometric System[J]. Chinese Journal of Lasers, 2017, 44(12): 1210002.