基于3×3耦合器的分布反馈激光器振动传感解调算法  

Demodulation Algorithm of Distributed Feedback Laser Vibration Sensor Based on 3×3 Coupler

作　　者：孔明阳 樊融 初凤红 卞正兰 张政 KONG Ming-yang;FAN Rong;CHU Feng-hong;BIAN Zheng-lan;ZHANG Zheng(Electronic Information Engineering College,Shanghai University of Electric Power,Shanghai 201306,China)

机构地区：[1]上海电力大学电子与信息工程学院,上海201306

出　　处：《科学技术与工程》2023年第21期9113-9121,共9页Science Technology and Engineering

基　　金：国网上海市电力公司依托工程项目(SGSHGJ00JGJS2100341)。

摘　　要：采用分布反馈(distributed feedback, DFB)激光器作为传感头,搭建了一种基于3×3耦合器的光纤振动传感系统。在基于微分交叉相乘算法(NPS)的基础上,提出了一种新的解调算法——反演微分交叉相乘算法(iNPS)。算法利用3×3耦合器三路对称的优点,采用3×3耦合器输出的两路信号反演出第三路信号,对三路信号校正后采用NPS算法对振动信号进行解调,系统采用两个光电探测器,与传统的NPS算法相比,降低了系统的成本及复杂程度。对iNPS算法与使用两路信号进行解调的微分交叉相乘算法进行仿真分析,比较了两种算法在不同输入振动信号的信噪比和3×3耦合器的不同非对称度条件下的解调结果。结果表明,在振动信号信噪比为32 dB的情况下,iNPS算法的信纳比比NRL算法信纳比提高了37.4 dB,总谐波失真率(total harmonic distortion, THD)下降了28%。并且iNPS解调算法可以在3×3耦合器三路信号不对称的情况下解调出振动信号。Distributed feedback(DFB)laser is used as the sensing head to build a vibration sensing system with a 3×3 optical fiber coupler.Based on the differential cross-multiplication algorithm(NPS),a novel demodulation algorithm which named as inverted differential cross-multiplication algorithm(iNPS)was proposed.Taking advantage of the symmetrical characteristic of 3×3 optical fiber coupler,the two channels output optical signals of the 3×3 optical fiber coupler were used to deduce the third channel optical signal,then the three channels output optical signals were corrected and NPS algorithm was used to demodulate the vibration signal.Two photodetectors were adopted to reduce the cost and complexity of the system compared with the traditional NPS algorithm.The iNPS algorithm and the differential cross-multiplication algorithm(NRL)using two channel optical signals for demodulation were simulated and analyzed.The demodulation results of iNPS and NRL algorithms with different signal-to-noise ratio input vibration signals and different asymmetry conditions of 3×3 optical fiber coupler was compared.The results show that when the signal-to-noise ratio of the vibration signal is 32 dB,the SINAD of the iNPS algorithm increases by 37.4 dB compared with the NRL algorithm,and the total harmonic distortion rate(THD)reduces by 28%.iNPS demodulation algorithm can demodulate the vibration signal under the condition that the three signals of the 3×3 optical fiber coupler are asymmetric.

关 键 词：分布反馈激光器 3×3耦合器 微分交叉相乘 信纳比 

分 类 号：TN247[电子电信—物理电子学]