Research On Peak-to-Average Power Ratio Reduction Algorithm Based On OFDM System

For the high-speed transmission system of underground cable,the channel of the logging cable has a relatively long trail due to its narrow effective bandwidth,resulting in a low data transmission rate of the system.Therefore,the OFDM technology with channel orthogonal superposition can be used in underground cable system to obtain more underground information at the same time.But it is OFDM symbol itself sub-channels orthogonal to each other,so there is a problem of high peak-to-average ratio,this problem will give some linear components put forward strict requirements,and may affect the overall system performance.This mainly focuses on the issue of high peaks in downhole OFDM technology.Three main techniques for suppressing peak-to-average power ratio are studied and simulated.The article first briefly introduced the principle,advantages and disadvantages of OFDM systems,and the high-speed transmission model of underground cables,and gave a introduction to the reasons for the peak-to-average ratio.Then,it simulated the typical algorithms in predistortion and coding technologies.The characteristics of these two algorithms and their applicability in the cable transmission system are summarized.In the scrambling algorithm,the advantages and disadvantages of the mapping method and the partial sequence transmission method are selected through MATLAB simulation.In the partial transmission sequence method,a comprehensive analysis is made on several major factors that affect the performance of the system.Considering the high temperature of the underground cable transmission system itself complicated environment,put forward the application of the PTS method of joint segmentation in the system,in order to solve the trade-off problem of suppression of peak-to-average ratio performance and smaller computational complexity.