University of Tasmania
In this paper, the authors address the effect of various system parameters on the spectral efficiency of Wavelength Division Multiplexing (WDM) systems. Three types of WDM systems were investigated: Unconstrained Modulation with Coherent Detection (UMCD) system, Constant Intensity Modulation with Coherent Detection (CIMCD) system, and Unconstrained Modulation with the Direct Detection (UMDD) system. Expressions are derived and presented to assess the spectral efficiency of these systems in the linear regime only. Simulation results are presented to assess the effect of various system parameters such as amplifier noise figure, number of spans and span length on the spectral efficiency.