基于导频ICI自消除的OFDM系统时变信道估计  

Time-varying channel estimation in OFDM systems based on ICI self-cancellation of pilots

作　　者：丁勇[1] 欧阳缮[1,2] 谢跃雷[2] 肖海林[2] 

机构地区：[1]西安电子科技大学电子工程学院,陕西西安710071 [2]桂林电子科技大学信息与通信学院,广西桂林541004

出　　处：《系统工程与电子技术》2014年第8期1632-1637,共6页Systems Engineering and Electronics

基　　金：国家重点基础研究发展计划(973计划)(2008CB317109);国家自然科学基金(60972084;61261018);广西自然科学基金(2013GXNSFFA019004);广西教育厅科研立项项目(201106LX156)资助课题

摘　　要：在基于分段线性模型的正交频分复用(orthogonal frequency division multiplexing,OFDM)时变信道估计中,存在模型参数估计精度受到载波间干扰(inter-carrier interference,ICI)影响的问题。为此,本文采用ICI自消除技术,抑制了导频子载波的ICI,改善了模型参数的估计性能。此外,还推导了单抽头Jakes信道条件下模型参数估计均方误差的表达式,理论分析表明,与基本的分段线性模型方法相比,本文方法可以使均方误差下降约13dB。仿真结果验证了在多抽头信道和大的多普勒扩展条件下,本文方法也能明显提高ICI抑制能力,从而得到更好的系统误码性能。For time-varying channel estimation in orthogonal frequency division multiplexing （OFDM）sys-tems,the estimation accuracy of parameters of the piece-wise linear model is affected by inter-carrier interfer-ence （ICI）.In view of this point,the ICI self-cancellation technique is utilized to mitigate the ICI at pilot subcar-riers,resulting in improvement of the estimation performance.Meanwhile,the expression of the mean square error of model parameter estimation for the single-tap Jakes’channel is derived.Theoretical analysis demon-strates that the mean square error of parameter estimation obtained by the proposed method approximately de-creases 13 dB comparing with that by the basic piece-wise linear model approach.Numerical simulation results show that the proposed algorithm can also obviously improve the performance of ICI suppression in the case of multi-tap channel and large Doppler spread,leading to better system error performance.

关 键 词：正交频分复用 信道估计 分段线性模型 载波间干扰抑制 

分 类 号：TN929.5[电子电信—通信与信息系统]