Research On PTS Algorithm For Peak-to-average Power Ratio Reduction In OFDM System

Orthogonal Frequency Division Multiplexing(OFDM)System has the features of low implementation complexity,ability to resist frequency selective fading,etc.It is one of the core technologies of the 4G.However,the high peak-to-average power ratio(PAPR)is one of the main drawbacks of OFDM,which restricts the development of OFDM technology.According to the above problem,this thesis mainly studied the rejection of PAPR in OFDM system.Firstly,this thesis introduces the background of the research,the basic principle of OFDM system and makes a brief description of the development and status;this thesis also illustrates the necessity of PAPR through describing the advantages and disadvantages.The Partial Transmit Sequence(PTS)is studied and improved mainly in this paper.Secondly,for the high computational complexity of traditional PTS,this thesis introduces several sub optimal algorithms and improves the PTS-ISLS which has better PAPR performance.The first improvement is taking each line of Hadamard matrix as a scrambling to multiply the initial phase.After that,the line with the lowest PAPR will be transmitted.This method can reduce the influence of the initial phase which is randomly generated.The second improvement is initialize multiple phases to reduce the limitation of single initial phase.Finally,in order to achieve the best effect of reducing the PAPR,the two improvements are combined,and the combined algorithm,PTS-MILS-H is proposed.The simulation of the algorithm is carried out,and the simulation results show that the improved algorithm has good PARP performance and low computational complexity.This thesis also analyzes the performance of GA-PTS.By introducing the idea of cyclically shifted sequence in time domain,the number of the candidate signals is...