消除调制深度影响的相位生成载波解调方法  

Phase Generated Carrier Demodulation Method Eliminating Modulation Depth Influence

作　　者：孙抗[1,2] 何梦阳 韩毓 SUN Kang;HE Mengyang;HAN Yu(School of Electrical Engineering and Automation,Henan Polytechnic University,Jiaozuo,Henan 454003,China;Henan Key Laboratory of Intelligent Detection and Control of Coal Mine Equipment,Jiaozuo,Henan 454003,China)

机构地区：[1]河南理工大学电气工程与自动化学院,河南焦作454003 [2]河南省煤矿装备智能检测与控制重点实验室,河南焦作454003

出　　处：《光子学报》2022年第6期185-194,共10页Acta Photonica Sinica

基　　金：国家自然科学基金(No.62173040);河南省科技攻关项目(No.202102210092);河南省高等学校青年骨干教师培养计划(No.2021GGJS056)。

摘　　要：针对相位生成载波解调算法严重依赖于调制深度,解调准确性和稳定性不高的问题,在传统PGC-Arctan算法框架中引入微分自相除运算环节,消除两路混频信号中调制深度的影响,再将两路信号进行相除得到包含相位信息正切平方项的信号,最后通过开方和反正切运算实现振动信号的解调。对不同调制深度和不同信噪比的信号解调仿真结果表明,该算法能够消除调制深度的不利影响,相比于其他常见的算法具有更好的解调效果。搭建实验平台进一步对仿真结果进行验证,实验数据表明,在不同的调制深度下,该算法的幅值误差最小为0.105%,总谐波失真最小为0.068%。此外,算法动态范围最高可达62.5 dB。综合分析结果验证了该算法能够有效地抑制调制深度影响,体现了其良好的稳定性和抗噪性,在高性能光纤振动传感系统中具有良好的应用前景。With the continuous development of basic theories and high performance devices,distributed optical fiber acoustic sensing technology has gradually transitioned from the qualitative detection stage to the quantitative detection stage and has been widely used in various applications.Demodulation of disturbance signal is indispensable for quantitative detection,so many demodulation methods intended for optical fiber sensing systems have been derived.The PGC(Phase Generation Carrier)technology has been widely used in optical fiber acoustic sensing systems due to its outstanding advantages of simple structure,high sensitivity,wide dynamic range,good linearity,and strong timeliness.According to the demodulation method type,the PGC technology can be mainly divided into the PGC-DCM(Differential and Cross Multiplying)algorithm and the PGC-Arctan algorithm.In terms of demodulation performance,the PGC-DCM algorithm has relatively high requirements on a circuit and is susceptible to interference from hardware facilities,especially system light intensity disturbances.In contrast,the PGC-Arctan algorithm is less sensitive to light intensity disturbances and has relatively low circuit requirements,but it has high requirements for the modulation depth of the system and faces the problem of phase unwinding.To address this limitation of modulation depth,this study proposes a method that introduces the differential self-division operation in the traditional PGC-Arctan algorithm framework to eliminate the influence of the modulation depth.Theoretical analysis shows that by introducing the differential self-division operation,the first-order and second-order Bessel function values of C can be eliminated,thereby eliminating the influence of the modulation depth drift on demodulation.Then,the original vibration signal is obtained through the square root operation and the arctangent operation.Using the simulation platform to analyze and compare the proposed algorithm and other common algorithms from two aspects:different modulation dept

关 键 词：相位生成载波 光纤振动传感器 相位调制深度 总谐波失真 

分 类 号：TN29[电子电信—物理电子学]