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应用科学学报 >

2013 , Vol. 31 >Issue 2: 142 - 146

DOI: https://doi.org/10.3969/j.issn.0255-8297.2013.02.006

通信工程

OFDM系统的时频同步优化

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  • 1. 北京交通大学轨道交通控制与安全国家重点实验室，北京100044
    2. 北京交通大学电子信息工程学院，北京100044
    3. 河海大学计算机与信息学院，南京211100
赵军辉，博士，副教授，IEEE高级会员，研究方向：无线通信和射频识别技术，E-mail: jhzhao@ieee.org

收稿日期: 2011-09-15

  修回日期: 2012-03-16

  网络出版日期: 2012-03-16

基金资助

国家自然科学基金（No.61172073, No.61001068）；轨道交通控制与安全国家重点实验室（北京交通大学）自主研究课题基金（No.RCS2011ZT003）；中央高校基本科研业务费专项资金（No.2013JBZ001）；教育部新世纪优秀人才支持计划基金（No.NCET-12-0766）资助

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Optimization of Time-Frequency Synchronization in OFDM System

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  • 1. State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiaotong University, Beijing 100044, China
    2. School of Electronic and Information Engineering, Beijing Jiaotong University, Beijing 100044, China
    3. College of Computer and Information Engineering, Hohai University, Nanjing 211100, China  

Received date: 2011-09-15

  Revised date: 2012-03-16

  Online published: 2012-03-16

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摘要

研究了多径衰落信道下OFDM系统的时频同步算法，分析了传统算法定时不准确的原因，提出了一种优化方法，并基于一个对称PN序列来完成时频同步. 通过寻找滑动相关求和值的第1个下降沿完成定时同步，给出了使用滑动求和值搜索窗口大小的选取方法，同时在频率同步中引入修正相关计算的概念. 仿真结果证明了该
算法在多径信道，特别是第1径不是最强径情况下的稳定性和优越性。

关键词： 正交频分复用; 定时同步; 频率同步; 多径衰落信道

本文引用格式

赵军辉1,2， 吕宸1， 谭国平3 . OFDM系统的时频同步优化[J]. 应用科学学报, 2013 , 31(2) : 142 -146 . DOI: 10.3969/j.issn.0255-8297.2013.02.006

Abstract

This paper studies joint synchronization in OFDM systems under multipath fading, and analyzes the reason of timing error in the existing algorithms. An optimized joint synchronization algorithm using PN sequence is proposed. The algorithm achieves time synchronization by looking for the first falling edge
of the sliding correlation sum value, chooses a size of the search window for the correlation sum value. Modified correlation calculation is introduced in the frequency synchronization. Simulation results show stability and superiority of the new algorithm under multipath environment, especially when the first path is not the strongest.

Key words：  orthogonal frequency division multiplexing; timing synchronization; frequency synchronization; multipath fading channels

参考文献

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[7]      YANG Suckchel, SHIN Yoan. A robust joint estimator for OFDM timing and frequency offsets based on PN codes [C]//IEEE Consumer Communications and Networking Conference, 2005.1: 577-579.
[8]      赵军辉，吕宸. 多径衰落信道下OFDM系统定时同步优化 [J]. 北京交通大学学报, 2011,35(3): 91-93.
ZHAO Junhui, LÜ Chen. An optimized estimation method for OFDM system under multipath fading channels [J]. Journal of Beijing Jiaotong University, 2011, 35(3): 91-93.
[9]      LI Ying Hui, MINN Hlaing. Robust and consistent pilot designs for frequencyoffset estimation in MIMO OFDM systems[J]. IEEE Transactions on Communications, 2008,56(10):1737-1747.
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