Research On A New OFDM Peak-to-average Ratio Reduction Algorithm Based On Subcarrier Switching

Orthogonal Frequency Division Multiplexing(OFDM)technology has become a research hotspot in the field of wireless communication because of its high frequency efficiency,strong anti-interference ability and strong resistance to multipath effect.However,OFDM signals also have the problem of high Peak to Average Power Ratio(PAPR).This paper focuses on how to reduce the Peak to Average Power Ratio of OFDM signals.Firstly,the theoretical basis of OFDM technology is introduced in detail and the reasons for the formation of peak to-Average ratio are analyzed.Three kinds of peak-to-mean ratio suppression technologies of OFDM signals existing at home and abroad are briefly introduced.Then,in view of the algorithm of Null-Data Subcarriers Switching algorithm of high computational complexity of this problem,the switching of three kinds of improved algorithm is proposed,respectively is local optimal solution instead of global optimal solution of climbing the mountain switching peak clipping algorithm,the data switching subcarrier grouping in order to reduce the traverse range of grouping random switched peak clipping algorithm and fixed switching sub-carriers spacing in each group of grouping equidistant switching peak clipping algorithm,then mountain climbing switching algorithm and grouping equidistance algorithm are combined to further reduce the computational complexity,the simulation results prove the effectiveness of the four kinds of algorithms.Then,the Iterative Clipping Filtering(ICF)algorithm in pre-distortion class technology was deeply studied.Aiming at the shortcoming that SOICF(Simplified Optimized Iterative Clipping Filtering)algorithm could not be applied to low threshold conditions,an Modified OICF(Modified Optimized Iterative Clipping Filtering,MOICF)algorithm was proposed.Through the method of curve fitting,this algorithm makes the waveform of peak canceling signal approximate to the waveform of Clipping noise.When the threshold value is reduced,the peak Clipping effect can still be guaranteed.Furthermore,an Adaptive Modified Modified Modified Clipping Filtering(A-MOICF)algorithm is further proposed.Finally,sub-carriers switching algorithm and other algorithms fusion scheme of indepth study,this paper discusses the compatibility of the algorithm selection and integration scheme,the framework of Switching-Tone Reservation fusion algorithm is proposed,simulation results show that the traditional Tone Reservation algorithm can reduce the peak to Average ratio of original OFDM signal from 10.3 d B to 7.1 d B,but after the fusion,the scheme can reduce the original signal the peak to Average ratio to 6.1 d B.