Comparative Analysis of different Coding Formats for 40 Gb / s System with Various Dispersion Compensation Techniques

This paper presents an analysis based on comparison among NRZ, CSRZ, DB and DPSK modulation format for a single channel 40 Gb/s system. The analysis is done for three different compensation schemes namely, pre compensation, post compensation and symmetric compensation. Because of the increasing demand of data throughput, speed of optical communication system is increasing rapidly to cope with the requirement. But for higher bit rate there are some limitations due to the presence of nonlinearities and dispersion in the optical fiber. Here the performance is analyzed using four spans each of 50 km through eye diagram, Q factor and ASE. ASE is observed at the end of four spans and a comparison is made among the compensation formats.