The Analysis And Implementation Of Optical OFDM Transmission System

With the development of communication technology and the continuous improvement of the communication requirements, optical communications show two clear trends:single-channel transmission data rate increased significantly, close to 100Gb/s; network must have the ability to dynamically adjust quickly. But when the data rate up to 100Gb/s, the traditional compensation fiber segments have become expensive and time consuming, the system is difficult to accurately achieve dispersion compensation, and the calculation of OFDM due to its good characteristics in the frequency domain by complex operations, accuracy can easily compensate for fiber dispersion, so people consider OFDM technology for optical communications, namely, optical orthogonal frequency division multiplexing system O-OFDM.The issue is the National Natural Science Foundation:"Research on key technologies of intelligent optical networks" (60672025) one of the research. Therefore, this need for optical access network high-speed, large capacity, low cost, around the orthogonal frequency division multiplexing in optical networks in the specific application, for a more in-depth and comprehensive studies; and proposed a novel low sampling rate D/A converter optical OFDM system. As a result, high-speed, optical OFDM system design is simple and the practical application of the theory has a certain significance and more important reference value. The following briefly describes the major work done this:1.Optical OFDM Transmission System for the research status has done a full investigation. Comparison of the optical focus of the traditional single-carrier OFDM system and optical transmission systems, and summarizes the OFDM technology can become the key technology of high-speed optical transmission systems the advantage of the Department;2.Summarized the optical basic principles of OFDM system design, focusing on analysis of its three key signal processing and synchronization technology. Meanwhile, according to the different ways of detecting optical receiver, described the light of today some of the major implementation scheme of OFDM systems;3.Focus on analysis of the different cyclic prefix lengths, optical fiber dispersion system for direct detection of the bit error rate, and further analysis, when the binary bit-rate increase when the dispersion in order to ensure the system capacity of the anti, OFDM symbol The design parameters of the problem;4.Around the system, the maximum distance that can be transferred for analysis. Verify the OFDM symbol in a given design parameters of the conditions, the maximum transmission distance of the link existence and gives it a specific mathematical expression. Then the simulation is verified, were changed when the binary bit rate, modulation and the number of subcarriers, the system can change the maximum distance transmission;5.Presents a low sampling rate based on optical OFDM system. That way only the actual number of samples sent to participate in all the inverse Fourier transform half the number of subcarriers, the equivalent reduction of D/A converter sampling rate requirements. At the same time, the way through the system simulation, respectively, based on such a design of bilateral and single sideband with optical OFDM system performance simulation, demonstrated its feasibility.This paper is the summary during the study of theory and the actual development, is divided into six chapters:The first chapter is the paper's introduction, mainly for orthogonal frequency division multiplexing optical networks can be used in the background, key technology and its advantages are briefly described, and explained the background of this thesis, the significance The key research objectives and content;The second chapter describes the optical system to the basic principle of OFDM system design, focusing on analysis of its end to end signal transmission model and the synchronization of three key technologies. Meanwhile, the detection method based on optical receiver (direct detection and coherent detection) is different, summarizes some of the main light of today's implementation scheme of OFDM systems;The third chapter of the cyclic prefix length for different discussed optical fiber dispersion system for direct detection of the bit error rate, and further analysis, when the binary bit-rate increase when the dispersion in order to ensure the system capacity of the anti, OFDM symbols associated parameter design problem. Then, around the system, the maximum distance that can be transferred for analysis. Verify the OFDM symbol in a given design parameters of the conditions, the maximum transmission distance of the link existence and gives it a specific mathematical expression. Finally, a way to verify the simulation, were changed when the binary bit rate, modulation and the number of subcarriers, the system can change the maximum distance transmission;The fourth chapter presents a low sampling rate based on optical OFDM system. That way only the actual number of samples sent to participate in all the inverse Fourier transform half the number of subcarriers, the equivalent reduction of D/A converter sampling rate requirements. At the same time, this chapter the way through the system simulation, respectively, of such design based on the bilateral and single sideband with optical OFDM system performance simulation, demonstrated its feasibility;The fifth chapter summarizes the paper's main results and innovation, the paper also points out the problems to be resolved and further research were discussed.