In The High-speed Optical Fiber Communication System Simulation And Realization Of Ofdm Modulation Demodulation Technology

Due to its robustness to degrade dispersion effect, no need for dispersionmanagement and efficient use of the spectrum, optical orthogonal frequency divisionmultiplexing (OFDM) is proposed as one possible schemes for the next generation ofhigh-speed optical communication system, and it has gained much interest in theoptical fiber communication community.In this thesis, the research and development trends of O-OFDM system isconcluded, and then the design and implementation of the high-speed O-OFDMcommunication system is discussed.In the design of the O-OFDM system, modeling and simulation is needed first, andthen analyzing its main performance and the possibility to achieve it is also needed. Adesign of O-OFDM system at the speed of20Gbit/s is given first, then this system ismodeled based on Matlab; the influences of Finite-Length Discrete Transforms, TimingSynchronization and Polarization Mode Dispersion to the system are discussed. Afterthat,a scheme of high-speed O-OFDM communication system is achieved.Based on the model and simulation of the system, the design and implementation ofelectric signals part is achieved. In this process, the crucial part is OFDM modulation,and OFDM modulation is IFFT-FFT. The radix-4-based64points IFFT-FFT core isdesigned based on Quartus2, then functional and timing simulation verification is done.The core has high efficiency, and can reach he highest throughout capacity of11.7G S/S(Giga symbols per second). Using this IFFT core, the O-OFDM system has thetransmission capacity of46.8Gbit/S at most.Nowadays, people demand communication systems with larger transmissioncapacity to send more messages. Some advices to increase the O-OFDM system’stransmission capacity, for example, Wavelength Division Multiplexing and PolarizationMultiplexed, are proposed.