湍流信道下指向误差对自适应副载波调制性能的影响  

Effect of Pointing Error on Adaptive Subcarrier Modulation Performance in Turbulent Channel

作　　者：陈丹[1] 鲁萌萌 刘艳蓉 Dan Chen;Mengmeng Lu;Yanrong Liu(School of Automation&Information Engineering,Xi'an University of Technology,Xi'an,Shaanxi 710048,China)

机构地区：[1]西安理工大学自动化与信息工程学院,陕西西安710048

出　　处：《光学学报》2020年第22期44-52,共9页Acta Optica Sinica

基　　金：国家自然科学基金(61771385);陕西省重点研发计划(2020GY-036);西安市科技计划(2019217814GXRC014CG015-GXYD14.21)。

摘　　要：基于未对准衰落(即指向误差)和Malaga湍流分布的联合概率密度函数,采用Meijer G函数推导自适应多进制相移键控(MPSK)调制系统的平均误比特率和中断概率渐近表达式。接收机半径一定时,通过调整光束束腰半径和抖动标准差参数值,可获得系统最优误比特率。当束腰半径与接收机半径之比wz/a=10且抖动标准差与接收机半径之比σs/a=1.5时,非自适应二进制相移键控(BPSK)系统平均误比特率曲线下降最快;而wz/a=5,σs/a=1.5时,自适应MPSK系统频谱效率和平均误比特率均达到最优。当未对准衰落一定且平均电信噪比较小时,自适应系统平均误比特率和中断概率主要受未对准衰落影响,但随着平均电信噪比的增加,受湍流的影响增大。Meijer G function is used to derive asymptotic expressions of average bit error rate and outage probability of adaptive M-ary phase-shift keying(MPSK)modulation system based on joint probability density function of misaligned fading(i.e.,pointing error)and Malaga turbulence distribution.When receiver radius is fixed,the optimal bit error rate can be obtained by adjusting the beam waist radius and jitter standard deviation.When the ratio of the beam waist radius to the receiver radius is wz/a=10 and jitter standard deviation to the receiver radius isσs/a=1.5,the average bit error rate curve of non-adaptive binary phase-shift keying(BPSK)system drops the fastest.The average bit error rate and spectral efficiency of the adaptive MPSK system are both optimal when wz/a=5 andσs/a=1.5.When the misaligned fading is constant and average electric signal-to-noise ratio is small,the average bit error rate and outage probability of adaptive system are mainly affected by the misaligned fading,but with the increase in the average electric signal-to-noise ratio,the influence of turbulence increases.

关 键 词：光通信 无线光通信 Malaga湍流 未对准衰落 自适应调制 频谱效率 平均误比特率 

分 类 号：TN929.1[电子电信—通信与信息系统]