摘要
因斯-高斯(IG)光束在复杂信道传输中具有较好的抗干扰能力。为此设计并搭建了基于模拟海洋湍流信道的激光通信实验平台,详细研究IG光束在海洋湍流信道下光束信号的传输及通信特性。首先实验对比研究了不同海洋湍流强度条件下,IG光束和高斯光束传输后的光强闪烁指数、质心漂移和探测器接收功率情况;其次通过调制0.5~3 MHz频率的方波信号,进一步研究两种光束传输后调制信号波形失真特性;最后进行IG光束和高斯光束的7.5 Mbit/s通信性能对比实验。实验结果表明:IG光束的闪烁指数、质心漂移、功率抖动均优于高斯光束,且随着海洋湍流强度增加,IG光束闪烁指数和质心漂移改善能力增强,功率抖动改善能力降低。在不同模拟海洋湍流中,相同频率的IG光束调制方波波形失真度整体低于高斯光束。在误码率为3.8?10-3(前向纠错阈值)时,IG光束在不同注水高度信道、不同温度信道和不同盐度信道中的通信性能比高斯光束分别提高了0.8 dB、4 dB和2.5 dB。该实验结果可以为IG光束应用于水下激光通信提供参考。
Objective Ince-Gaussian(IG)beams are widely used in the fields of beam generation and application due to their unique beam structure and phase distribution.In free-space optical communication,especially in atmospheric turbulent channels,IG beams show better anti-interference ability than Gaussian beams.However,the ocean turbulent channel environment is more complex and changeable,and the impact on the beams is more serious.To study the beam and signal transmission and communication characteristics of IG beams in ocean turbulent channels,we systematically study the transmission characteristics of IG and Gaussian beams in simulated ocean turbulent channels.The results provide a reference for IG beams to be applied in underwater laser communication.Methods The transmission and communication experimental platforms of IG optical signals in simulated ocean turbulent channels are designed and built.The platform can simulate ocean turbulence with different intensities by changing parameters such as water injection height,water temperature,and salinity.Firstly,the intensity scintillation index,centroid drift,and detector received power of IG beams and Gaussian beams are experimentally compared under different ocean turbulence intensity channels.Then the waveform distortion characteristics of the modulated signals of the two beams are further studied by modulating the square wave signals of 0.5-3 MHz frequency.Finally,the communication performance evaluation experiment of IG and Gaussian beams is carried out by loading modulation 7.5 Mbit/s signals with field programmable gate array programming.According to the above comparative results,the transmission and communication characteristics of IG beams in ocean turbulent channels are obtained.are compared,including scintillation index,centroid drift,power jitter variance,waveform distortion,and the bit error rate(BER).When the water temperature increases from 40.1℃to 60.2℃,the performance advantage between the scintillation index of the IG beams and Gaussian beams increased from 15.5%to 21.8%.The performance advantage between centroid drift increased from 11.6%to 18.3%.However,compared with the Gaussian beams,the power jitter variance performance advantage of the IG beams reduced from 12.9%to 3.7%.The performance advantage between the waveform distortion of the square wave signal of the IG beams at the modulation frequency of 3 MHz decreases from 6.3%to 5.6%when the water temperature increases.Compared with Gaussian beams,the communication systems with IG beams as carriers have better BER performance.When the BER is 3.8×10^(-3)(forward error correction threshold),the communication performance of IG beams in three kinds of underwater channels is better than that of Gaussian beams.The communication performance of the IG beam is improved by O.8 dB at most in channels with different water injection heights,improved by 4 dB at most in channels with different temperatures,and improved by 2.5 dB at most in channels with different salinity.Moreover,the communication performance advantages of IG beams compared with Gaussian beams enhance with the increase in water injection height,temperature,and salinity.Conclusions The results of transmission experiments show that the scintillation index,centroid drift,and power jitter of the IG beams are better than those of the Gaussian beams.With the increase in ocean turbulence intensity,the improved ability of scintillation index and centroid drift of IG beams is enhanced,while the improved ability of power jitter is decreased.In different simulated ocean turbulence,the distortion of the modulated square wave of IG beams is lower than that of the Gaussian beams at the same frequency.The experimental results show that,when the BER is 3.8×10^(-3),the communication performance of IG beams in channels with different water injection heights,different temperatures,and different salinity is 0.8 dB,4 dB,and 2.5 dB higher than that of Gaussian beams,respectively.In summary,IG beams have a unique advantage in transmission and communication characteristics compared with Gaussian beams in ocean turbulent channels.
作者
张鹏
戴辉
何爽
范云龙
陈航
王圆鑫
南航
佟首峰
Zhang Peng;Dai Hui;He Shuang;Fan Yunlong;Chen Hang;Wang Yuanxin;Nan Hang;Tong Shoufeng(School of Optoelectronic Engineering,Changchun University of Science and Technology,Changchun 130022,Jilin,China;College of Communication Engineering,Jilin University,Changchun 130012,Jilin,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2023年第18期201-211,共11页
Acta Optica Sinica
基金
国家自然科学基金重点项目(62231005)
国家重点研发计划(2022YFB2903400)
吉林省教育厅基金(JJKH20220746KJ、JJKH20220771KJ)
关键词
因斯-高斯光束
海洋湍流
闪烁指数
质心漂移
功率抖动
波形失真度
Ince-Gaussian beams
ocean turbulence
scintillation index
centroid drift
power jitter
waveform distortion
