基于信道估计的OFDM定时同步算法  

OFDM timing synchronization algorithm based on channel estimation

作　　者：许炜阳[1] 周杰[1] 王雨晴[1] 吴玉成[1] 

机构地区：[1]重庆大学通信工程学院,重庆400044

出　　处：《吉林大学学报（工学版）》2016年第1期290-295,共6页Journal of Jilin University:Engineering and Technology Edition

基　　金：国家自然科学基金项目(61201177);重庆市自然科学基金重点项目(cstc2013jjB40004)

摘　　要：针对正交频分复用(OFDM)系统在多径衰落信道第一径不是最强径时存在定时错误,以及现有精同步算法漏检概率大的问题,提出利用信道冲激响应循环右移特性实现对第一径的精确检测。该算法先通过粗同步定位到能量最强径,再使用最小二乘(Least square)算法求出信道冲激响应,根据滑动窗口内能量变化判断各径所在位置,最后采用自适应门限法检测出第一径。理论分析和仿真结果表明:本文算法同已有算法相比,可降低精确符号同步的漏检概率,有效提高系统的定时性能。The timing errors in Orthogonal Frequency Division Multiplexing（OFDM）,which occur when the first path is not the strongest one in the multipath fading channel,would incur a high probability of miss detection.To solve this problem,a timing synchronization algorithm was proposed,which can be used to exploit the cycle-right-shift property of channel impulse response to estimate precisely the first path delay.In this algorithm,first,the delay of the strongest path was estimated through coarse synchronization.Then,the channel impulse response was obtained using the Least Square（LS）algorithm,based on which the location of each path was determined according to the difference in a sliding window.Finally,the first path was detected using the adaptive threshold approach.Theoretical analysis and simulation results show that,compared with the existing methods,the proposed algorithm can decrease the probability of miss detection and improve the system timing performance.

关 键 词：通信技术 正交频分复用 定时同步 第一径延时 最小二乘算法 

分 类 号：TN929.5[电子电信—通信与信息系统]