Comparative study of different modulation schemes in optical fiber communication system

Abstract

In this project, we investigate and comprehensively compare Non-return-to-zero (NRZ) with the advanced modulation schemes: carrier- suppressed return-to-zero (CSRZ) and Duo-Binary (DB) modulations using three approaches to compensate the dispersion: pre-compensation, post-compensation, and symmetric compensation at operating wavelength 1550 nm and 90km fiber length through computer simulations. The influence of the LASER input power has been studied at three bit rates: 5 Gbps, 25 Gbps, and 40 Gbps.The performance characteristics like bit error rate, Q-factor, and eye diagram are compared and discussed by simulating different cases using tables and graphs in order to compare the different results.