Performance Analysis of Optical Orthogonal Frequency Division Multiplexing Transmission Systems

Abstract

Orthogonal Frequency Division Multiplexing (OFDM) is very attractive modulation technique used in emerging broadband wireless and wired communication systems due to its spectrum efficiency and channel robustness. Orthogonal frequency division multiplexing belongs to a broader class of multicarrier modulation (MCM) in which the data information is carried over many lower rate subcarriers. Two of the fundamental advantages of OFDM are its robustness against channel dispersion and its ease of phase and channel estimation in a time-varying environment. The growing requirement for communication services and the tremendous expansion of the Internet are driving the development of high-capacity and flexible optical transport networks. Freshly a number of researches have made known that OFDM is a promising and capable technology for optical communications, although its application in the real optical systems is still under study. The objective of this dissertation is to analyze the performance of optical fiber based OFDM transmission systems and for this purpose Virtual Photonics Integrated (VPI) software is used which allows the design of many configurations regarding optical communications. Firstly, a combination of OFDM system and optical single side band modulation along with constellation adjustment method is presented to show perfect dispersion compensation and better sensitivity of OFDM systems than NRZ system. Secondly, a cost efficient architecture for optimized performance of WDM OFDM system with dual band transmissions (C and Lband) using hybrid Erbium Doped Fiber Amplifier (EDFA) – Raman amplifier is proposed. Thirdly, impact of non linear distortion in optical orthogonal frequency division multiplexing radio over fiber system (OOFDM-RoF) is analyzed and a novel approach of insertion of pilot tones for compensation of non linear distortion in optical OFDM-RoF system is proposed.