Efficient Modeling and Simulation of Wavelength Division Multiplexing Dual Polarization QPSK Optical Fiber Transmission

Abstract

Due to enormous growth in communications, wavelength division multiplexing (WDM) systems are popular because these systems allow us to expand the capacity of the networks without laying more optical fiber cables. In this thesis, we have systematically derived the coupled nonlinear Schrödinger (CNLS) equations, including a consistent definition of the complex envelope, Fourier transform, the state of polarization, and derivation under the engineering notation. After a discussion of coarse step based second order symmetrized split-step Fourier (SSSF) simulation method, which is applicable to the numerical solution of the CNLS equations, an analytical step-size selection based local error method is applied to the WDM optical fiber communication systems. With systematical simulation study of both standard single mode fiber (SSMF) fiber links and true-wave reduced slope (TWRS) fiber links. It is found that similar to the single channel systems, the global simulation accuracy for the vector propagation can be satisfied using the local error bound (LEB) obtained from a scalar propagation model for the same global error over a large range of simulation accuracy and differential group delay (DGD). Furthermore, carefully designed numerical simulations are used to show that the proposed local error method leads to higher computational efficiency compared to other prevalent step-size selection schemes in vector WDM simulations. The scaling of the global simulation error with respect to the number of optical fiber spans is demonstrated, and global error control for multi-span WDM simulations is proposed