Design And Implementation Of Symbol Synchronization Algorithm Based On Training Sequence In OFDM System

With the comprehensive popularization and rapidly development of mobile communication technology.The OFDM is a high-speed transmission technology with multi-carrier form,has the advantages of high spectrum efficiency,anti multipath and so on,make it become the core technology currently used in the fourth generation mobile communication system,and it has been widely concerned by the domestic and international academic circles.However,the OFDM system is very sensitive to the timing error of symbol synchronization.So it is very important to improve the performance of OFDM system to achieve accurate symbol synchronization.According to the research and improvement of OFDM symbol synchronization algorithm based on training sequence in this paper,combining the complementary relationship between Schmidl&Cox algorithm and Park algorithm in performance and their consistency on the training sequence,this paper presents a synchronous method of improved OFDM symbol,the method of the whole process is divided into coarse synchronization and fine synchronization estimation stage.Firstly,a coarse estimate of the Schmidl&Cox algorithm is used.Then the estimation window of the fine synchronization estimation is determined by the coarse synchronization estimation point.Finally,the Park algorithm is used to get the timing position of the symbol.The simulation results of Matlab show that the improved algorithm can keep the average square error(MSE)under the condition of high and low SNR compared with the existing algorithms.The symbol synchronization algorithm for OFDM hardware test is divided into functional test and performance test,the results show that the improved algorithm can implementation of OFDM baseband signal symbol synchronization,and can draw the constellation.In the EVM index,the result is below 5%.In the MSE index,when SNR is less than 8dB the results below 105,when SNR is greater than 8dB the results below 10,and are better than the existing algorithm.The OFDM symbol synchronization method in both function and performance meet the design requirements and indicators,can realize the symbol synchronization to the signal of the OFDM baseband system,and the research results have certain practical engineering value for the application of OFDM technology in communication system.