多媒体传感网中限幅OFDM的信道估计算法  

Channel estimation algorithm of clipped OFDM in wireless multimedia sensor networks

作　　者：解永生[1] 覃荣华[2] 周磊磊[1] 付耀先[1] 

机构地区：[1]中国科学院上海微系统与信息技术研究所无线传感器网络与通信重点实验室,上海200050 [2]中国科学院上海微系统与信息技术研究所微系统技术重点实验室,上海200050

出　　处：《华中科技大学学报（自然科学版）》2012年第8期123-128,共6页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家科技重大专项资助项目(2010ZX03006-003)

摘　　要：针对限幅正交频分复用(OFDM)系统中非线性失真导致信道估计性能瓶颈的问题,提出一种利用时间相关性的迭代信道估计算法.获取信道响应时,该算法综合运用了导频信息和历史信道信息,首先对硬判决后的OFDM符号进行限幅滤波,然后估计导频及数据子载波的非线性失真,最后进行信道再估计及符号再判决.理论分析及仿真结果表明:算法提高了信道估计和符号检测的准确度,而且算法只需1次再估计即可达到传统算法的均方误差理论极限,误码率性能提升了0.8dB.To eliminate the performance bottlenecks caused by nonlinear distortion in clipped OFDM（orthogonal frequency division multiplexing） systems,an iterative channel estimation algorithm utilizing time correlation was proposed,which was built by both pilot symbols and historical information.After hard decision,the reconstructed OFDM symbols were clipped.Then the nonlinear distortion of pilot and data symbols was estimated.After that,the channel was re-estimated and the data symbols were re-detected.The theoretical analysis and computer simulations show that the proposal increases the performance of channel estimation and symbols detection.Particularly,it approaches the theoretical limit of traditional method with only 1 channel re-estimation.Compared to traditional method,the algorithm increases the BER（bit error rate） performance by 0.8 dB.

关 键 词：无线多媒体传感网 信道估计 正交频分复用 峰均比 信道状态信息 信道增益 

分 类 号：TN911[电子电信—通信与信息系统] TN914[电子电信—信息与通信工程]