Channel Modeling And Signal Estimation Of Multi-Core Optical Fiber Transmission System Based On Non-Uniform Mode Field

With the increase of the amount of communication,people's demand for the capacity of the communication is increasing,Big data,cloud services,such as information technology,high-speed burst,the advantages of optical fiber is increasingly prominent,How to break the shackles of the traditional optical fiber technology,the high speed,large capacity and long distance transmission of optical fiber communication is both an opportunity and a challenge.The transmission capacity and transmission rate of the single core and single mode fiber have reached the bottleneck of transmission,And multi core optical fiber,multimode fiber in the transmission of the dimension of the ordinary single mode,single core transmission bottlenecks,based on pattern multiplexing and multi core optical fiber technology is becoming a research hotspot,has aroused the interest of scholars at home and abroad.In this paper,the characteristics of multimode and multi core transmission technology are analyzed.Because of domestic and foreign researches on the little mode multi core optical fiber transmission system,the research of the new type of optical fiber channel has not been realized,Through the simulation results and the design parameters of the fiber,a new type of fiber channel is designed,and the feasibility is demonstrated.In order to improve the simulation channel and the actual channel characteristics,the most effective method is to analyze and summarize the characteristics of the channels,and establish a multi core optical fiber channel model with the characteristics of the two channels.Signal through complex channel is bound to have a lot of damage,only the corresponding signal processing,recovery of the original signal,in order to achieve a large capacity,long distance of the core fiber transmission.So,after the establishment of the model of the multi core optical fiber transmission channel,the channel signal estimation method is studied,which has a more accurate demonstration of the multi core optical fiber transmission technology.The main research contents and main innovations of this paper are as well:(1)In this paper,the main technologies of the multi-core,less mode and less-mode multi-core fiber multiplexing system are studied.We analyzed and summarized the characteristics of the multi-core,less modes and less-mode multi-core fiber channel,and modeled and simulated the channel.When modeling,the main factors include the coupling between different cores and different modes,the attenuation,the chromatic dispersion,the polarization mode dispersion,the nonlinear effects and the signal damage in the link of the ordinary single mode fiber.After modeling and simulating to various channels,we proposed a model to the less modes multi-core optical fiber channel,which has an non-uniform mode distribution.And through the reasonable design of the fiber channel parameters,we can realize the characteristics of large capacity and long distance transmission with optical fiber.(2)In the light of the Channel modeling and analysis to multi-core,less modes and less-mode multi-core transmission channel,we propose a signal estimation algorithm for each channel.Firstly,we analyzed an improved LMS algorithm for estimating the length of training sequence,which is based on the coupling coefficient;For the less modes coupling fiber channel,we use the relatively simple ICA equalization algorithm;For the coupled equilibrium of less-mode multi-core channel,we use the MIMO algorithm of combining above two algorithms.We carried out simulation experiments with matlab for each channel,using the corresponding equalization algorithm,and the equilibrium effects are ideal.Thus,the practical application of the large capacity transmission of optical fiber is more closer.