Transmission Performance Research Of Multi-band Modulation Format In High-speed Optical Communication

Nowadays, with the rapid growth of internet business and all linds of new businessappear constantly, it makes the transmission rate of optical communication networkcontinues to grow. For single channel over40Gbps and high-speed opticaltransmission system, its core router interface will exceed100Gbps, those originallynot to consider nonlinear effect and polarization mode dispersion (PMD) effect becomeserious, optical signal quality deterioration, the data error rising sharply, these factorsreduce the transmission performance of the system. The new code modulation formats,as one of the key technologies studied in high-speed optical fiber communicationsystems, can effectively reduce the transmission loss, enhance the system’ s ability toresist dispersion and nonlinear effects and improve the spectrum efficiency and thetransmission performance of high-speed optical communication system. Due to thedifferent trasmissionsystems with different parameters, such as rate,length, spectrumwidth,fiber type,amplifier etc,so different transmission systems have the most suitablemodulation formats.However,the new type of multi-band modulation format is one ofthe important means to solve these problems.Aiming at the phase of multi-band modulation format and its transmissionperformance (including the dispersion tolerrance and nonlinear tolerrance and so on),the thesis conducted to deeply theoretical analysis, system model simulation andcomparision.At the same time, we will also be advanced coding modulation techniquecombined with polarization multiplexing and FDPC technology，and by seting thehigh-speed long-distance optical transmission syetem to simulate analysis of thetransmission performance of the syetem. Themain work included:1、Studied and mastered the generation and demodulation of the phase modulation ofmulti-band modulation formats (CSRZ-DQPSK/CSRZ-8DPSK/CSRZ-16DPSK).2、 Adopted the method of combining the theoretical analysis with the softwaresimulation, successfully built the high-speed single channel optical communicationsystem by using Matlab and OptiSystem, studied, analyzed and compared the resistant dispersion and nonlinear capability of the phase of multi-band modulation formats in thesystems. At the same time, We pointed out the dispersion tolerance and nonlineartolerance on the advantages and disadvantages. we have also studied the different waysof dispersion compensation effect on three kinds of multi-band modulation format.3、On the basis of above work, by means of theoretical analysis and numerical simula-Tion.we set up the100Gbps high-speed optical communication system POLMUX-CSRZ-DQPSK-WDM and analyzed its transmission performance from the followingfour aspects, syetem Q value along with the change of3dB bandwidth filtering curve,system of extinction ratio along with the change of optical pulse delay curve, syetem ofdifferential group delay(DGD) tolerance and non-linear tolerance of the system.