Damage Modeling, Evaluation And Optimization Strategy Of Transmission Performance For100G Optical Networks

Currently,100Gbit/s transmission technology in Optical Transport Network (OTN) continued to mature, and gradually began to commercial deployment. Meanwhile, coherent detected polarization-division multiplexed quadrature phase shift keying (PDM-QPSK) has emerged as the most promising solution for commercialized100Gbit/s transmissions. For such systems, as the chromatic dispersion (CD) and polarization-mode dispersion (PMD) can be elegantly compensated by using digital signal processing (DSP), nonlinear effects have been acting as the main limitation, especially those employing wavelength-division multiplexing (WDM). Therefore, optical network transmission performance evaluation and optimization technology and fast calculation method is urgently needed in order to realize better transmission performance in high-speed all-optical network.To solving this problem, the research about100Gbit/s PDM-QPSK coherent optical system with dispersion uncompensated (DU) and non-identical spans is described in this paper. Moreover, damage modeling, optical network transmission performance evaluation and promoting technology in this system is introduced. Three optimization technologies are also proposed to realize transmission performance improvement. In this paper, the main innovations and contributions are listed as follows:1. Physical layer nonlinear impairments modeling of100Gbit/s PDM-QPSK coherent optical systems with dispersion uncompensated (DU) is achieved under the influence of self-phase modulation (SPM), cross-phase modulation (XPM) and Four Wave Mixing (FWM). Fiber nonlinearity acts as additive Gaussian Noise (GN) in100Gbit/s PDM-QPSK coherent optical system with dispersion uncompensated (DU). Nonlinear impairments are derived analytically.2. The quality of transmission (QoT) estimation modeling of WDM system with non-identical spans is proposed. Meanwhile, the effectiveness of the modeling is verified by simulation. Since the nonlinear noise accumulates incoherently for each span in the DU systems, both the ASE and nonlinear noise can be summed up at the receiver under the Gaussian distribution assumption. Therefore, the SNR at the receiver can be expressed as a function of SNR in each span. Discrepancy between simulation and theory are within0.8dB under various configurations, showing quite good evaluation accuracy.3. Three optimization technologies are proposed to improve transmission performance, and the effectiveness of the technologies are verified by simulation. The optimal transmitter launch power and corresponding optimal gains of EDFAs are derived by the function of QoT estimation modeling. The optimization technologies based on the location of EDFA and the difference between the optimal gain configuration and the original gain configuration are proposed in a single point-to-point DU link with non-identical spans, which not only improves the QoT effectively, but also minimizes the number of EDFAs that need to be adjusted as few as possible.