基于直流偏置光正交频分复用的水下光通信自适应光强探测电路设计  

Design of Adaptive Light Intensity Detection Circuit for Underwater Optical Communication Based on Direct-Curren-Biased Optical Orthogonal Frequency Division Multiplexing

作　　者：任秀云[1] 李秀娜 张延超 张志华 欧阳辰穗 唐子帆 Ren Xiuyun;Li Xiuna;Zhang Yanchao;Zhang Zhihua;Ouyang Chensui;Tang Zifan(School of Information Science and Engineering,Harbin Institute of Technology,Weihai,Weihai 264209,Shandong,China)

机构地区：[1]哈尔滨工业大学(威海)信息科学与工程学院,山东威海264209

出　　处：《光学学报》2023年第24期151-160,共10页Acta Optica Sinica

基　　金：国家重点实验室开放项目(SKLLIM 1915);山东省重大科技创新工程(2020CXGC010705);哈尔滨工业大学科学研究与创新基金(ITDZMZ001803)。

摘　　要：针对水下光通信受湍流、生物活动等影响引起链路失准,或通信距离改变导致接收光强变化较大的问题,结合直流偏置正交频分复用光信号的特点,提出了一种自适应光强探测电路。该电路通过自动增益控制技术调整对接收信号的放大倍数,输出稳定的电信号。首先对自适应光强探测电路的相关参数进行理论分析和仿真验证,然后设计研制该电路并进行空气信道和水下信道的实验测试。结果表明,该电路能够实现对不同强度光信号的自适应调节,输出电信号峰峰值基本稳定在600 mV左右,波动范围为-3.3%~3.3%。Objective With the expanding marine exploitation,high-speed long-reach underwater wireless communication has caught extensive attention.Compared with underwater acoustic communication and radio frequency communication,underwater wireless optical communication(UWOC)features a high data rate,great confidentiality,and large data capacity.Nevertheless,the challenging underwater environment exerts a significant effect on underwater light transmission.Absorption,scattering,and communication distance change may lead to a great variety of detection optical intensity,and the link misalignment between the transmitter and receiver caused by turbulence can also realize this.Nonlinear distortion or loss of receiver signal will be resulted in.Optical receivers generally employ variable gain amplification circuits to process dynamic signals to mitigate these effects.However,existing UWOC systems have some shortcomings.Limiting amplifier is generally applicable to optical communication systems of on-off keying modulation digital transmission.Automatic gain control(AGC)circuit generally adopts a detector to detect the changes in output signal amplitude to form a gain control feedback loop.In this feedback loop,the time to reach a stable operating state is affected by its characteristics,and the AGC adjustment time is fixed,with hysteresis in gain control.We propose an adaptive light intensity detection circuit,which utilizes automatic gain control technology to adjust the amplification of the received signal and output stable electrical signals.This adaptive light intensity detection circuit has the advantages of fast response time and better real-time performance.We hope that our proposed method can improve the practicality of UWOC systems,aiming for optical communication systems in complex environments.Methods Our proposed circuit is based on the characteristics of the direct-current-biased optical optial orthogonal frequency division multiplexing(DCO-OFDM)signal.The circuit takes advantage of the proportional relationship betw

关 键 词：水下光通信 自适应光强探测 自动增益控制 对数放大电路 

分 类 号：TN929.1[电子电信—通信与信息系统]