水下无线光通信系统信道冲激响应拟合函数对比分析  

Comparative Analyses of Fitting Functions for Channel Impulse Response in Underwater Wireless Optical Communication Systems

作　　者：谭跃跃 李岳衡[1] 黄平[1] 刘陕陕 居美艳[1] Tan Yueyue;Li Yueheng;Huang Ping;Liu Shanshan;Ju Meiyan(School of Computer and Information,Hohai University,Nanjing,Jiangsu 211100,China)

机构地区：[1]河海大学计算机与信息学院,江苏南京211100

出　　处：《光学学报》2021年第11期53-62,共10页Acta Optica Sinica

基　　金：中央高校基本科研业务费项目(2019B15714);国家自然科学基金(61832005)。

摘　　要：鉴于目前尚未有用于拟合清澈海洋水质信道冲激响应(CIR)曲线的函数,提出一种使用双指数函数拟合清澈海洋水质CIR曲线的方法,并与现有的其他4种拟合函数如单伽马、逆高斯、双伽马、CEAPF进行对比,以揭示所提方法的优势。在不同海水水质、传输距离、接收机视场角条件下,研究5种拟合函数各自的拟合效果和适用范围,并通过蒙特卡罗仿真实验加以验证。理论分析和仿真结果表明:所提双指数函数不仅在清澈海洋水质下的拟合效果很好,浑浊海港水质下的拟合效果也相当不错,特别是在短距离(比如10 m)清澈海洋水质、各种传输距离和视场角的浑浊海港水质下,皆超越其他4种函数的拟合性能。原用于拟合大气环境CIR的单伽马函数也可用于拟合清澈海洋和浑浊海港两种水质的CIR;采用逆高斯函数拟合清澈海洋、近海海岸、浑浊海港三种水质的CIR都有较大误差;双伽马函数则可较好地拟合近海海岸和浑浊海港这两种浑浊水质下的CIR,但却无法拟合清澈海洋的CIR;CEAPF函数总体上可用于拟合三种水质的CIR,且取得了不错的拟合效果。Owing to the lack of a particular function to fit the channel impulse response(CIR)curves in clear ocean water,a method of fitting CIR curves of clear ocean water using double exponential function is proposed in this article.The proposed double exponential function is compared with four other well-known fitting functions—single Gamma,inverse Gaussian,double Gamma,and CEAPF—to show its superiority.Moreover,we compare and analyze the fitting performance and working range of these five functions under different conditions of seawater quality,link range,and field of view(FOV)of the receiver,and these are verified by Monte Carlo simulation experiment.Both theoretical analyses and simulation results suggested that the proposed double exponential function could achieve an accurate fitting performance not only in clear ocean water but also in harbor water and could outperform the four other functions,especially in a short link range of clear ocean water(e.g.,10 m)and in harbor water case with different link ranges and FOVs.From the results,the single Gamma function used to match the CIR curves in the atmospheric environment could also be used to fit the ones in clear ocean water and harbor water,whereas the inverse Gaussian function deviated the CIRs under any working case with larger errors;the double Gamma function could fit the CIR of coastal water and harbor water but could not fit that of clear ocean water;the CEAPF function could generally fit well with the CIRs in the three ocean water qualities and obtain good fitting results.

关 键 词：光通信 水下无线光通信 信道冲激响应 蒙特卡罗仿真 数据拟合 双指数函数 

分 类 号：TN929.3[电子电信—通信与信息系统]