The Algorithm Research Of Reducing PAPR Of OFDM System

Orthogonal Frequency Division Multiplexing is the core technology of next generation wirelesscommunication. It has many merits, including high bandwidth efficiency, resistance to multipathinterference ability, and strong anti-frequency selective fading capability, etc. Because of its higherpeak-to-average power ratio, there are many restrictions in application. The thesis is to study and finda more effective PAPR suppression algorithm of OFDM system.First, this thesis analyzes the research status quo on the problems of suppression PAPR ofOFDM system at home and abroad, illustrates the basic principles of OFDM technology, shows theblock diagram of OFDM system, and describes the advantages and disadvantages of OFDM systemand its key technologies. From the definition and the probability distribution of PAPR of OFDMsystem, the thesis introduces the research on the problems of the OFDM system, and summarizes thethree main technologies of PAPR: pre-distorting algorithm, coding algorithm and scramblingalgorithm.Secondly, focusing on genetic algorithms and simulated annealing algorithm, discusses some ofthe key issues of theparameter settings; through analysis algorithm principle and its realizationprocess gives detailed algorithm flowchart; Put forward a new algorithm SA-GA combined geneticsimulated annealing algorithm for the first time through combining the advantages,disadvantages andalgorithms innovative features of the two algorithms, developed detailed algorithm flow and flowcharts of the new algorithm, and then gives some optimization tips to the new joint SA-GA algorithm.Then, the genetic algorithm, simulated annealing algorithm and an improved greedy algorithmMGA acts on the PTS-OFDM systems, MATLAB simulation results show that the optional SA-PTSalgorithm and the GA-PTS algorithm can be used in a high performance requirements system, whileGA-PTS algorithm is more superior in a real-time and PAPR high performance requiring systems.Finally, the paper proposes a new genetic simulated annealing SA-GA algorithm PTS-OFDMsystem for solving the problem of high PAPR, simulation experiments show that in the same numberof iterations, PTS-SAGA algorithm appears in the same lower than the probability of PTS-GAalgorithm the PAPR value reduced by about1dB. Further, in the same probability, PAPR valuePTS-SAGA algorithm only higher than the PTS algorithm not exhaustive0.4dB.