基于数字锁相环的水下高速光通信解调算法设计实现  

Design and implementation of demodulation algorithm for underwater high-speed optical communication based on digital PLL

作　　者：薛婧文 秦文虎[1] 赵晓燕 周军 杨敏 XUE Jingwen;QIN Wenhu;ZHAO Xiaoyan;ZHOU Jun;YANG Min(School of Instrument Science and Engineering,Southeast University,Nanjing 210096,China;Nanjing Advanced Laser Technology Research Institute,Nanjing 210038,China)

机构地区：[1]东南大学仪器科学与工程学院,南京210096 [2]南京先进激光技术研究院,南京210038

出　　处：《激光杂志》2023年第9期24-29,共6页Laser Journal

基　　金：江苏现代农业产业关键技术创新资助项目(No.CX(20)2013)。

摘　　要：为了满足水下高速激光通信技术工程化应用的需要,对水下光信号传输进行了建模仿真,对数字锁相环电路进行了性能分析,设计了一种基于多相位时钟恢复原理的改进型数字锁相环水下光通信系统解调算法,弥补了传统数字锁相环不适用于高速解调的缺点。首先通过滑动均值滤波和自适应阈值判决进行输入数据预处理,提高了系统的信噪比;其次基于改进的多相位数字锁相环法进行数据同步,提高了数据解调的可靠性和准确性。在现场可编程逻辑门阵列(FPGA)上完成了算法实现,并基于不同水质和距离进行了系统测试。实验结果表明,基于该解调算法的通信系统,在输入调制信号速率15 Mb/s、误码率10-6条件下,清澈海水水质中的通信距离为20 m,沿海海水水质中的通信距离为10 m,浑浊海水水质中的通信距离为5 m。In order to meet the needs of engineering application of underwater high-speed laser communication technology,modeling and simulation of underwater optical signal transmission were carried out,and the performance of digital phase-locked loop circuit was analyzed.An improved demodulation algorithm of digital phase-locked loop underwater optical communication system based on the principle of multi-phase clock recovery was designed,which made up for the shortcomings of traditional digital phase-locked loop which was not suitable for high-speed demodulation.Firstly,the input data is preprocessed by sliding mean filtering and adaptive threshold decision,which improves the signal-to-noise ratio of the system.Secondly,data synchronization based on improved multi-phase digital phaselocked loop method improves the reliability and accuracy of data demodulation.The algorithm is implemented on field programmable logic gate array(FPGA),and the system is tested based on different water quality and distance.Experimental results show that the communication system based on the demodulation algorithm,under the conditions of input modulation signal rate of 15 Mb/s and bit error rate of 10-6,the communication distance is 20 m in the water quality of clear sea water,10 m in the water quality of coastal sea water,and 5 m in the water quality of turbidity sea water.

关 键 词：可见光通信 水下通信 脉冲位置调制 数字锁相环 

分 类 号：TN929.1[电子电信—通信与信息系统]