Research On DP-QPSK Coherent Optical Communication System Simulation And Error Detection Technology

Since the 60s of the last century,the optical fiber communication was firstly proposed,and now has been applied in all aspects.With the development of social technology,the demand for the speed of communication transmission has been put forward higher requirements,especially the mobile video,Internet of things,big data processing and cloud computing.The QPSK coherent optical communication which once become a key point has been proposed and studied again.At present,the transmission network of 10G and even 40G has been widely used,but can not meet the needs of the people gradually.We need to improve the transmission rate of current fiber.Based on the consideration of future higher rate of optical networks,the DP-QPSK(double polarization quadrature phase shift keying)modulation with polarization multiplexing transmission and coherent detection for the high spectrum efficiency and high efficiency,high channel SNR and loss tolerance advantage,get the favour of many experts and system vendors.The paper analyzes the performance of 40Gbps DP-QPSK coherent optical communication system built on the simulation platform of Optisystem,and several important factors affecting the performance of the system.Besides,dectecting the error rate as an important to measure the performance of the communication system.On the basis,getting the main factors which can improve the transmission rate of DP-QPSK coherent optical communication transmission system.The main works is as follows:1.On the basis of further investigation of DP-QPSK coherent optical communication system,the paper expatiates on the QPSK modulation format and DP-QPSK coherent optical communication system,and the working principle of optical devices in the transmitter and receiver.At the same time,the author study seriously and become skilled at the Optisystem simulation software to build the coherent optical communication system for 40Gbps DP-QPSK on the Optisystem simulation platform.Setting the parameters and debugging makes the system transmit signals.Analysising the details of the light signal transmission process as well as the optical power,spectral,polarization and other factors in the transmission process.Through measuring optical signal-to-noise ratio and bit error rates of the system,we can analyze the impact of input optical power,the laser linewidth,the gain of EDFA and other factors on the communication system with MATLAB.2.On the detailed introduction of the bit error principle,definition and detection principle,and working principle of PRBS code generator and high speed transceiver module of the high speed bit error tester.Based on the existing components and technology,I design some reasonable schemes to detect the bit error rate of DP-QPSK coherent optical communication system with a high speed.