Research On Synchronization And Channel Estimation Technology In OFDM System

Orthogonal Frequency Division Multiplexing(OFDM) technology has already become one of the wide band mobile communication system research hot spots,the future fourth generation mobile communication system will have the possibility to use this technology very much,but the two key technology which will greatly affect the performance of OFDM system—synchronization and channel estimation algorithms still need further improving.This thesis firstly studies synchronization technology,based on the analysis of the influence of each kind of synchronization error on the system performance, the thesis focuses on the ML algorithm based on the cyclic prefix and S&C algorithm based on the training sequence and its improved algorithms,then carries on the simulation of various algorithms.Then,the thesis focuses on the channel estimation,mainly researches the pilot-aided estimation technology,after the thesis studies the channel estimation algorithms based on the LS critirion or the MMSE criterion and their improved algorithms,the thesis researches the interpolation algorithms of non-pilot positions,at last,the thesis carries on the simulation analysis of each algorithm.Based on the research in the above,the thesis presents a combined synchronization and channel estimation algorithm for OFDM baed on maximum likehood,in order to maximize the use of resources and improve the performances of system.Simulation results show the effectiveness of the proposed estimation algorithm.