模分复用系统中模式轮循策略的对比研究  

Comparative Research on Mode Permutation Strategies in Mode-division Multiplexing Systems

作　　者：高天宇 王彦泽 刘亚平 杨志群 张林[1,2] GAO Tianyu;WANG Yanze;LIU Yaping;YANG Zhiqun;ZHANG Lin(Key Laboratory of Opto-electronic Information Technology of Ministry of Education and Tianjin Key Laboratory of Integrated Opto-electronics Technologies and Devices,Tianjin University,Tianjin 300072,China;Peng Cheng Laboratory,Shenzhen 518038,China)

机构地区：[1]天津大学光电信息技术教育部重点实验室&天津市集成光电子技术与器件重点实验室,天津300072 [2]鹏城实验室,广东深圳518038

出　　处：《光通信研究》2025年第1期8-12,共5页Study on Optical Communications

基　　金：国家自然科学基金资助项目(62105241);天津市自然科学基金资助项目(21JCQNJC00540)。

摘　　要：【目的】模分复用技术是突破单模光纤传输系统容量极限的关键技术。在少模光纤链路中,随着传输距离的增大,模间色散导致的脉冲展宽使接收端多输入多输出算法的复杂度变高,这是限制模分复用系统实现长距传输的重要原因之一。而应用模式轮循方法能够有效压缩脉冲展宽,减小模式相关损耗,是目前实现长距离大容量模分复用系统传输的主流技术路径。但模式轮循策略数量众多,性能存在差异,探究更适用于长距大容量模分复用系统的模式轮循策略成为亟待解决的难题。【方法】文章提出了一种模式轮循策略匹配光纤群时延排布的设计思路,设计了配合群时延对称型少模光纤使用的对称模式轮循(MFMP)策略。通过仿真平台建模,分析了文章所提MFMP模分复用系统传输性能,并进行了6模复用传输系统实验验证。【结果】文章基于MFMP策略,使用28 GBaud正交相移键控信号,结合群时延对称型少模光纤,开展了822 km的6模实验传输。在616 km处,与传统依次模式轮循(CMP)和模群轮循(CMGP)策略相比,信号的脉冲展宽分别压缩了37%和6%,Q值分别提升了3.0和0.4 dB。【结论】文章所提MFMP策略能够有效压缩脉冲展宽,提高系统传输Q值,通过仿真和实验分别验证了其性能优于传统的2类轮循策略,该工作为实现基于模式轮循的长距大容量模分复用传输提供了理论依据和实验指导。【Objective】Mode-division multiplexing is a key technology to break through the capacity limit of single-mode fiber systems.In the few-mode fiber links,the pulse broadening caused by intermodal dispersion increases the complexity of multiple-input-multiple-output algorithms in the receiving terminal,which is one of the important reasons for limiting the implementation of long-haul transmission in mode-division multiplexing systems.The application of mode permutation methods can effectively compress pulse broadening and reduce mode-dependent loss,making it a mainstream technological approach for achieving long-distance,high-capacity mode-division multiplexing system transmission.However,there are numerous mode-permutation strategies with varying performance,and exploring mode-permutation strategies that are more suitable for long-distance,high-capacity mode-division multiplexing systems has become an urgent problem to be solved.【Methods】In this paper,we propose that the mode permutation strategy should match the mode group delay distribution of the fiber.Besides,we design a Mirror-Flipped Mode Permutation(MFMP)strategy based on few-mode fibers with symmetric mode delay.By modeling on a simulation platform,the transmission performance of mode-division multiplexing system based on the proposed MFMP is analyzed and verified through 6-mode multiplexing transmission experiments.【Results】In this paper,based on the proposed MFMP strategy,822-km 6-mode transmission over a mode-delay-symmetric few-mode fiber is experimentally demonstrated,carrying quadrature phase shift keying signals at 28 GBaud.At 616 km,compared to Cyclic Mode Permutation(CMP)and Cyclic Mode-Group Permutation(CMGP)methods,the signal pulse broadening is compressed by 37%and 6%,and the Q-factor is increased by 3.0 and 0.4 dB,respectively.【Conclusion】The proposed MFMP strategy can effectively compress pulse broadening,and improve the Q-factor of the system,while the advantages of this method over traditional two types of mode permutation str

关 键 词：模分复用 少模光纤 模式轮循 

分 类 号：TN929[电子电信—通信与信息系统]