一种OFDM定时同步与载波频偏估计算法  

A timing and frequency estimation algorithm for OFDM

作　　者：黄慧[1] 程鹏[1] 张朝阳[1] 仇佩亮[1] 

机构地区：[1]浙江大学信息与电子工程学系,浙江杭州310027

出　　处：《电路与系统学报》2009年第2期62-67,共6页Journal of Circuits and Systems

基　　金：浙江省自然科学基金重点项目(Z104252);浙江省科技计划项目(2005C21005);国家自然科学基金(60472080)

摘　　要：本文提出一个有效的利用周期性前导字的OFDM定时同步与频偏估计算法。算法分为两个步骤,首先根据前导字的特殊结构对Schmidl&Cox算法进行改进,将Schmidl&Cox算法中平台的检测变成单个峰值的检测,并由单峰的位置和复值可同时准确地估计符号定时和分数倍频偏;然后提出"相位差分序列",利用该序列的相关性对整数倍频偏进行估计。文中针对AWGN信道和SUI信道对算法进行了仿真,结果表明本文算法较其它算法具有更好的估计性能和鲁棒性。Robust timing and frequency synchronization in OFDM systems is addressed in this paper. First, an improved synchronization algorithm is presented, which converts the ＂plateau＂ in the traditional Schmidl＆Cox algorithm into a single peak, and the position of the peak can be used to simultaneously estimate symbol timing and fractional frequency offset. Then, an integer frequency offset estimation algorithm using the differentiated sequence of the preamble is proposed, which is robust to the remaining timing offset. The performance of the proposed algorithm is evaluated in both AWGN and SUI multipath fading channel. Simulation results show that the proposed algorithm achieves a better estimation performance than existing algorithms.

关 键 词：OFDM 前导字 定时频偏估计 

分 类 号：TN911.23[电子电信—通信与信息系统]