摘要
在水下无线光通信系统中,海洋湍流会造成接收光强闪烁效应,从而导致通信质量降低,以及通信系统性能恶化,影响接收信号的误码率和信噪比。利用单输入多输出(SIMO)系统分集合并接收可以有效抗闪烁。基于SIMO水下无线光通信系统,提出一种自适应动态合并接收算法,利用多条支路接收信号,根据支路信号的信噪比质量,自适应控制各支路信号的开启状态与合并策略。与传统分集合并方法相比,该方法有效缩短各支路工作时间,在不同闪烁指数下,分析了海洋湍流对各支路信号误码率以及信噪比的影响,通过仿真与实验验证了所提算法的抗闪烁性能,证实了该算法在保证通信系统稳定性的前提下能够节省能耗,为减小水下闪烁效应对通信信号的影响以及降低通信系统能耗提供了技术支撑。
Objective To mitigate the scintillation effect caused by oceanic turbulence on received light intensity and reduce its influence on the performance of underwater wireless optical communication(UWOC)systems,we propose an adaptive combining algorithm based on traditional anti-scintillation methods to enhance the system’s stability and save energy.Methods Based on a single-input-multiple-output(SIMO)system,our proposed adaptive dynamic combining algorithm uses multiple branches to receive signals,and the activation state and combining strategy of each branch are adaptively controlled according to the signal-to-noise ratio(SNR).We conduct simulations to evaluate bit error rate(BER),outage probability,and energy consumption performance of two-branch and three-branch systems under channel conditions with a scintillation index of 0.32 and Gaussian white noise variance of 0.49.Additionally,under the condition of two-branch reception,we simulate the influence of turbulence intensity on UWOC system performance by placing 1,2,and 3 heating rods in a water tank to verify the performance of the adaptive algorithm under two-branch reception.The results confirm the effectiveness of our proposed adaptive combining algorithm.Results and Discussions To demonstrate the performance of our proposed algorithm,we first conduct a simulation analysis under channel conditions with a scintillation index of 0.32 and noise variance of 0.49,focusing on the performance of both two-branch and three-branch configurations.The analysis covered BER,outage probability,and energy consumption.The results indicate that the anti-scintillation performance of the three-branch combination is superior to that of the two-branch combination,with lower BER and outage probabilities in the three-branch setup(Figs.7 and 9);however,the energy consumption is higher for the three-branch reception.Additionally,a comparison between the performance of our adaptive algorithm and traditional algorithms reveals that our proposed adaptive algorithm exhibits BER and outage performance only slightly lower than that of the maximum ratio combining(MRC)algorithm while outperforming the equal gain combining(EGC)and selection combining(SC)algorithms(Figs.6-9).From the perspective of energy consumption,our adaptive algorithm demonstrates superior performance,effectively reducing energy usage.Furthermore,we conduct experiments to validate the performance of our proposed adaptive algorithm under two-branch reception across different scintillation index conditions(Table 1),confirming the effectiveness of the adaptive algorithm presented in this study.Conclusions The results show that our proposed adaptive combining algorithm exhibits excellent anti-scintillation performance and outperforms traditional combining algorithms in terms of energy efficiency.Simulation results for two-and three-branch anti-scintillation performance demonstrate that the system’s anti-scintillation capability improves with the number of branches,but merely increasing the number of branches offers limited enhancement.It cannot infinitely improve the system’s BER,SNR,and outage performance,and system energy consumption also rises with more branches.Additionally,by using two-branch reception,we simulate turbulence intensity by adding one,two,and three heating rods in a 1 m water tank to assess the influence on the UWOC system.This experiment validates the advantages of our proposed adaptive algorithm in terms of BER,outage performance,and energy consumption.Our adaptive combining algorithm achieves BER and outage performance slightly lower than MRC but superior to EGC and SC algorithms,while showing better energy efficiency than traditional methods.
作者
张建磊
张友为
华丹琪
窦雨昂
党鹏涛
Zhang Jianlei;Zhang Youwei;Hua Danqi;Dou Yu’ang;Dang Pengtao(School of Electronic Engineering,Xi’an University of Posts&Telecommunications,Xi’an 710121,Shaanxi,China)
出处
《光学学报》
北大核心
2025年第2期161-171,共11页
Acta Optica Sinica
基金
装备预研与教育部联合基金(8091B032130)。
关键词
水下无线光通信
单输入多输出系统
自适应接收
合并算法
underwater wireless optical communication
single-input-multiple-output system
adaptive reception
combining algorithm
