Research On Signal Processing Mode Division Multiplexing Communication Experiment System

In recent years,due to the rapid development of network services in the new era such as cloud computing,Internet of Things,the Internet,and big data,as well as the deep integration of contemporary industries and their deep integration,the demand for optical network bandwidth has exploded in the form of exponential power.The capacity of the communication system has higher requirements.So far,optical communication systems mainly use single-mode fiber as the transmission medium,but the nonlinear effect largely affects the quality of the signal transmitted by single-mode fiber.The network capacity is gradually approaching the Shannon limit.Therefore,researchers at home and abroad have studied various technologies for improving network capacity,and have expanded the capacity by using the degree of freedom of mode.Therefore,the modular multiplex(MDM)technology using small-mode fiber(FMF)as the transmission medium has emerged.The mode-less fiber has a limited number of independent orthogonal modes,such as the LPxy mode,which can be multiplexed and transmitted as an independent channel of the MDM communication system,so that the transmission capacity of the MDM communication system can be improved.However,in the actual DCH optical fiber communication system communication system,mode coupling(MC)and differential mode group delay(MGDM)and other damage will seriously degrade the transmission performance of the modular-multiplexed communication system,so how to solve the mode coupling and difference The problem of pattern group delay and other issues,the demultiplexing of the received signal will become the key to the problem.Around the above problems,so far,most of the research is still in the simulation experiment stage,and the MDM system is mostly a simulation experiment system built by VPI.Based on the actual MDM communication experiment system,the model reuse/deselection is a mode selective photonic lantern produced by Olkin Optics.The MDM communication experiment system is built with OOK modulation,and the signal processing is completed according to the actual received signal of the system.use.Firstly,the orthogonality of modes in the mode-less fiber and the damage mechanism based on the mode-multiplexed communication system of the small-mode fiber are analyzed.Then the signal equalization algorithm of the mode-less fiber-optic modular-multiplexed communication system is studied.Based on this,the algorithm is built.Based on photon lanterns,the experimental system of small-mode fiber-optic analog-to-multiplex communication is explored,and the demultiplexing effect of FD-LMS algorithm and FD-ICA algorithm on the experimental system of mode-mode fiber-multiplexed communication is studied.The experiment has achieved good results.result.The specific work of this paper is as follows:From the perspective of optical waveguides,the theoretical orthogonality of modes in small-mode fibers is theoretically analyzed.The structure and working principle of the small-mode fiber-optic modular-multiplexed communication system are expounded.The two major impairments of the mode-mode fiber-division-multiplexed communication system are analyzed:mode coupling and differential mode group delay.The structure of the MDM communication system and the related technologies of signal processing are introduced.2.Research on modular multiplex communication experiment system based on FD-LMS signal processing algorithm.Firstly,the FD-LMS algorithm is theoretically studied,and the feasibility of the algorithm for damage compensation of MDM communication system is clarified.Then,a 3×3 MDM communication experiment system is built,and the transmission performance and error performance of the system under different transmission distances are experimentally studied.Finally,for the poor transmission quality,the experimental results verify the compensation performance of this algorithm for the damage in the MDM communication experimental system.3.Research on modular multiplex communication experiment system based on FD-ICA signal processing algorithm.First,theoretical analysis is carried out around the FD-ICA algorithm.Subsequently,a 2×2 MDM communication experiment system was built,and the transmission performance and error performance of the system without transmission distance were experimentally studied.Finally,the experimental results verify the compensation performance of this algorithm for the damage in the MDM communication experimental system.