Study On Synchronization Algorithm In OFDM System

In the recent years,the technology of orthogonal frequency division multiplexing(Orthogonal Frequency Division Multiplexing,OFDM)have attracted considerable research interests.The spectrum utilization and strong anti-multipath fading of OFDM has been used in digital video broadcasting for terrestrial(DVB-T),ground integrated service digital transmission(SDB-T)and asymmetric digital subscriber line(ADSL).At present,people are generally believed that OFDM technology is the mainstream technology of the fourth generation mobile communication system.As a multi-carrier modulation technology,OFDM is very sensitive to synchronization error,so the synchronization is a very important part to it.In the synchronization algorithm based on training symbols,training symbol does not carry information and reduces the effectiveness of information transmission.Therefore,this paper studies the OFDM synchronization technology based on CP,mainly includes the following three parts:First of all,introduced the basic principle of OFDM.We presents the multi-carrier,the basic structure of basic OFDM,and each module discussed.The key technology is discussed in detail,including why to use the CP,the advantages of using IFFT/FFT and the basic steps of engineering design are described and analyzed in detail.Then,introduces the basic principle of synchronous OFDM system,and analyzes the three different synchronization causes and effects of information.We discussed it from the point of view of practical engineering application,especially on timing synchronization and carrier synchronization for the impact of information.Finally,the maximum likelihood based on CP classic(ML)algorithm,set correlation algorithm is studied,the mathematical model established by ML algorithm and set related mathematical algorithm,and using MATLAB simulation tool.Because the ML algorithm and the correlation algorithm has certain limitation,in order to improve the performance,we proposed a new algorithm-block relative algorithm,and through software simulation platform in the AWGN,the multipath fading channel,the bit error rate and mean square error frequency,timing made analysis and simulation,and compared with the maximum likelihood algorithm classic and set algorithm.