| The21st century is the century of light. With the rapid development of communicationtechnology, people have more demand on the access network bandwidth. Because of the rapidinnovation in optical networks, the next generation optical network OFDM-PON has beenextensive attention and recognition in the industry. The bandwidth allocation technology forOFDM-PON is the most important in its key technologies, and the bandwidth allocationalgorithm is the core technology of the bandwidth allocation. Relative to the static bandwidthallocation with simple structure, dynamic bandwidth allocation can change the bandwidthallocation according to the needs of users in time, utilizing the bandwidth more fully, toensure the fairness between users. This subject is based on OFDM-PON system as theresearch object, researching on its transmission performance and dynamic bandwidthallocation algorithm.Firstly, the OFDM optical fiber transmission system is researched. The RF OFDM andthe optical OFDM are in comparison, analyzing the transmission characteristics of opticalOFDM. Model and simulate OFDM fiber channel transmission by using MATLAB software,to observe the impact of transmission performance by changing different parameters of thetransmission system. At the same time, channel estimation is researched, simulating andanalyzing the importance of the channel estimation in the transmission process, to verify thefeasibility of the OFDM transmission in the optical fiber, to obtain the transmissioncharacteristics of OFDM optical fiber transmission.Secondly, traditional CP algorithm is researched. Introduce the algorithm principle byalgorithmic process and distribution style, and analyze its inadequacies. Apply the traditionalCP algorithm to OFDM-PON system, using OPNET network simulation software to modelOFDM-PON system and simulate traditional CP algorithm. By changing the EF, AF, BEbusiness load, observe the delay characteristic of the different types of business. Analyze theresults of simulation, to obtain the transmission characteristics of OFDM-PON system usingtraditional CP algorithm.Finally, the traditional CP algorithm is improved, and improved algorithm is researched.The improved algorithm is improved from the traditional CP algorithm by the uploadingbusiness style and internal ONU allocation style. Apply the improved algorithm to OFDM-PON system and model the system. By changing the EF, AF, BE business load,observe the system link utilization and delay characteristics of the different types of business.Compare the simulation results with the simulation results of traditional CP algorithm, toobtain the transmission characteristics of the OFDM-PON system using improved algorithm,reflecting the superiority of the improved CP algorithm. |
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