多径信道下OFDM系统的采样频率偏移盲估计方法  

Blind estimation algorithm of sampling frequency offset for the OFDM system over multipath channels

作　　者：李兵兵[1] 孙珺[1] 刘明骞[1] 

机构地区：[1]西安电子科技大学综合业务网理论及关键技术国家重点实验室,陕西西安710071

出　　处：《西安电子科技大学学报》2014年第4期87-93,共7页Journal of Xidian University

基　　金：国家自然科学基金资助项目(61271299);国家"863"高技术研究发展计划资助项目(2007AA01Z288);高等学校学科创新引智计划资助项目(B08038)

摘　　要：为提高实际的非合作通信系统中正交频分复用系统的采样频率偏移估计性能,提出了一种多径衰落环境下、非合作通信系统中、时频同步之前的正交频分复用系统采样偏移估计的新方法.该方法先利用一种改进循环谱对谱相关点进行粗估计,再利用另一种改进的循环谱对谱相关点进行细估计,最后根据估计出的相关点上循环谱的相位值,经跳变转化、最小二乘直线拟合后计算出相位变化率,得到正交频分复用系统采样偏移的估计值.仿真结果表明,该方法在多径信道条件下,比现有的盲估计方法具有更高的估计精度与性能.In order to improve the performance of sampling frequency offset（SFO） estimation for the Orthogonal Frequency Division Multiplexing（OFDM） system in practical non-cooperation communications, this paper proposes a new sampling frequency offset estimation for the OFDM system estimation algorithm in multipath fading channels and the non-cooperation communications system.The proposed algorithm first uses an improved cycle spectrum to make a coarse estimation of the relative point,and then estimates accurately the relative point through another improved cycle spectrum.Finally,the estimated values of sampling frequency offset are obtained by the rate of change of the phase of the cycle spectrum in the relative point after j umping phase change and least square fitting.Simulation results show that the proposed algorithm has not only higher estimation accuracy but also better performance over multipath channels.

关 键 词：采样频率偏移 正交频分复用 盲估计 循环谱 多径信道 

分 类 号：TN911.7[电子电信—通信与信息系统]