Reseach On High Speed DP-QPSK Coherent Optical Communication System

With the advent of the era of big data on the Internet and the rapid development of cloud computing technology,there are higher requirements for the communication capacity and spectrum utilization of the communication system.Coherent optical communication system has many advantages,such as long transmission relay,high sensitivity of receiver,communication capacity and processing of transmission link damage in electrical domain.Polarization multiplexing normal phase shift keying modulation code type(DP-QPSK)has many advantages as an alternative code type of future coherent optical communication 400 G transmission scheme.In this paper,the DP-QPSK coherent communication transmission system with high rate and long distance transmission is simulated in depth.The main research contents and results are as follows:Firstly,the principle of DP-QPSK modulated transmitter and coherent detection receiver is described,and the major factors causing signal degradation in coherent optical transmission system are analyzed,such as chrominance dispersion,polarization mode dispersion and nonlinear effect.Then studied the the receiver of DP-QPSK coherent optical communication transmission system in the electric field on transmission link damage compensation recovery of digital processing algorithm,and researched DP-QPSK coherent optical communication system transmission receiver under the DSP,such as estimating the chromatic dispersion compensation algorithm,the signal dynamic equilibrium algorithm,the compensation algorithm of carrier frequency offset.Modules of DSP were built with excellent estimation and compensation performance.Secondly,the simulation platform was built as a whole with Optisystem software and Matlab software.The communication performance of the system was analyzed through the system output eye graph,and the communication system was improved to enable it to transmit 800 km and maintain good communication performance.The DP-16 QAM coherent optical transmission communication system is simulated under the global variable parameters of 300 Gbps transmission rate and 120 km transmission distance.The system communication performance is good and an optimization scheme is proposed for the system.