Research On The Generation And Application Technology Of Multicarrier

In the past decade,with the continuous acceleration of the development of the Internet,the global broadband services has grown rapidly,such as short-video,small-video,webcast and other services become popular.As artificial intelligence has gradually become the current research hotspot,the demand of cloud computing,big data and other corresponding technologies is bigger and bigger;In recent years,5G technology has been proposed and it's more and more close to commercial,the attention on 5G technology is increasing.The above phenomena show that people's demand for the network not only focus on bandwidth,but also on the lower delay and higher speed.At present,the research in this field usually focus on single fiber to achieve Tb/s or Pb/s transmission system.In order to achieve high speed and large capacity transmission,optical fiber communication system often uses wavelength division multiplexing technology.The key is using multi-wavelength light source at the transmitting end.Multiple lasers of different wavelengths can be used as light sources in optical fiber communication systems,but this scheme is not only expensive,but also difficult to deploy which decreases the practicability.At present,the multi-carrier generation scheme based on Phase modulator(PM),Mach-Zehnder modulator(MZM)and recirculating frequency shift(RFS)has been studied,but there are some problems,such as high driving voltage,low carrier flatness and lower efficiency,so it is of great research significance to study the low cost and high efficiency multi-carrier generation scheme and its application.Aiming at the above problems,this paper first studies the research background,significance and development status of multi-carrier light source,then analyzes the principle of the main devices in the multi carrier source system,such as PM,MZM,optical amplifier,etc.,and then puts forward two new multicarrier source generation systems,including the generation principle and implementation scheme.On the basis of principle analysis,the performance simulation is carried out,and finally the application of multi-carrier in polarization mode dispersion monitoring is studied.The main research work is divided into the following parts:(1)Analyzes the advantages of multi-carrier light source and its development status at home and abroad.Study the principle of each device in electro-optical effect and multicarrier source system,such as phase modulator,MZM,etc.,gives the corresponding mathematical model,and lays a theoretical foundation for putting forward multicarrier source scheme.(2)A novel multicarrier generator based on dual parallel Mach-Zehnder modulator(DPMZM)is proposed,the theoretical derivation is made,and the mathematical model is given.The carrier fr-equency shift under the condition of small signal condition and large signal is analyzed,the simulation under ideal conditions is carried out,and the subcarrier with a carrier number of 60 and a flat degree of 0.6026dB is obtained under the condition of 30 cycles.In the case of cyclic 50 times,a subcarrier with a carrier number of 100 and a flat degree of 0.7769dB is obtained.In the case of cyclic 100 times,a subcarrier with a carrier number of 200 and a flat degree of 1.148dB is obtained.At the same time,the influence of the ASE noise introduced by EDFA on the output carrier noise ratio is analyzed,when the number of carriers is 50,compared with the output carrier under ideal conditions,and the output carrier noise ratio is about 5dB lower.(3)A novel frequency locking multi-carrier generator based on DE-MZM is proposed,which only needs a MZM and a phase modulator to produce cyclic frequency shift carrier.Made the theory analysis and the mathematical derivation to this scheme.Made the simulation under the ideal condition,when circulates 30 times,30 subcarriers with the flatness of 2.4dB are obtained,when circulates 50 times,50 subcarriers with the flatness of 4.8dB are obtained.(4)A PMD monitoring system based on multicarrier and SOA-XGM is proposed,the in:fluence of PMD on signal is analyzed,the principle of wavelength conversion based on SOA is studied,the structure of PMD monitoring system is given and the simulation is carried out by using OptiSystem.For the 10Gbits/s NRZ-4QAM signal,the PMD monitoring range can reach 100ps,and the influence of cumulative dispersion on the monitoring accuracy is analyzed,and the dynamic monitoring range is about 2dB when the cumulative dispersion is within 200ps.