Research And FPGA Implementation Of Synchronization Technology In Broadband Wireless Transmission System

With the rapid development and full popularization of wireless communication technology,spectrum resources are increasingly scarce.As a multi-carrier modulation technology,Orthogonal Frequency Division Multiplexing(OFDM)has the advantages of good antimultipath capability and high spectrum utilization.It has become one of the key technologies in the fourth and fifth generation mobile communication systems.In OFDM systems,symbol synchronization deviation will cause FFT window offset to cause Inter Symbol Interference(ISI),and carrier frequency offset will destroy the orthogonality between subcarriers and cause Inter Carrier Interference(ICI).These two kinds of synchronization errors will seriously affect the transmission performance of the OFDM system.Therefore,synchronization technology plays a vital role in OFDM systems.This work mainly includes the following points:Firstly,based on the background of the development of wireless communication and OFDM technology,the research status of synchronization technology in OFDM system at home and abroad is summarized.On this basis,the basic principle of OFDM system and the characteristics of channel model in wireless communication are introduced,and the influence of symbol synchronization error and carrier synchronization error on OFDM system is analyzed.Secondly,several classical OFDM symbol synchronization algorithms and carrier synchronization algorithms are studied,and the advantages and disadvantages of the classical synchronization algorithms are analyzed.Based on the classical algorithm,a new training sequence is designed,and the corresponding symbol synchronization algorithm and carrier synchronization algorithm are proposed.Under various channel conditions,the average deviation and mean square error of symbol synchronization estimation results,the mean square error of fractional frequency offset estimation and the correct rate of integer frequency offset estimation in carrier synchronization are simulated and analyzed,and the superiority of the algorithm is verified.Finally,the FPGA technology and its advantages are introduced,and the FPGA design scheme is given for the synchronization algorithm proposed in this paper,and the entire synchronization function module is implemented in FPGA.The structural design of the functional module is described in detail,and the behavioral level simulation is carried out.A test platform for board-level testing and a synchronous module test scheme are designed.In the case of ensuring that the board-level test results are the same as the Matlab fixed-point results,the board-level test results are compared with the Matlab floating-point results,the reasons for the errors are analyzed,and the correctness of the FPGA implementation scheme is verified.