OFDM系统中符号和频偏联合同步算法研究

Study on the Joint Algorithms of Symbol Timing Synchronization and Carrier Frequency Offset for OFDM System

正交频分复用系统(OFDM)对同步误差十分敏感,当存在同步误差时,会引起严重的载波间干扰(ICI)和符号间干扰(ISI)。在AWGN信道以及频率选择衰落信道下,对基于循环前缀最大似然算法进行了仿真。并提出了基于循环前缀叠加子导频的符号和频偏联合同步新算法,实现了整数倍频偏(IFO)估计,仿真分析表明该算法具有较好的性能,并且计算量小。

OFDM systems are extremely sensitive to synchronization error. When Synchronization error exists, inter-carrier interference and inter-symbol interference are introduced. This paper studies the OFDM system based on cyclic prefix and lots of simulations are given under AWGN and frequency selective fading channels. The new algorithm is put forward based on cyclic prefix, which adds pilots into information sequence in order to have the ability to get integer-frequency-offset estimate. The results of simulation analysis show that it is good in performance and low in complexity