The demand for bandwidth is getting higher and higher at the user side of the network with the growth of information society which has a directly effect on aggregation and core network. The provider should satisfy this grown demand on their networks in order to keep or even increase their customer base.
The main objective of this thesis is to let the reader get familiar with the analysis of high-order (multi) modulation formats which are capable to increase data rate and spectral efficiency. The implemented high order modulation structure cause further growth of the complexity but this is the only suitable method to reach the goal mentioned previously because of the limitations of spectrum allocation and technology.
The certain modulation formats are analyzed in a typical wavelength division multiplexed core network environment. In addition the increasing spectral efficiency is observed which is the consequence of polarization multiplexed scheme. We will see that the spectral efficiency and the quality of the network will change using different symbol lengths. Our goal is to find the optimal repartition of the previously mentioned parameters considering the nonlinear effects and optical noise. The thesis will guide the reader through the detailed quality parameters of the different modulation types. Comparing these characteristics the best one could be chosen for given network. The final edification of the thesis after evaluating the simulation results is that the best modulation type is the same like in the standard of 100 Gbps Ethernet which was publicized almost one year ago.