Blind estimation of multipath delays in OFDM systems  

作　　者：SHENG Bin YOU XiaoHu 

机构地区：[1]National Mobile Communications Research Laboratory,Southeast University,Nanjing 210096,China

出　　处：《Science China(Information Sciences)》2012年第6期1397-1401,共5页中国科学（信息科学）（英文版）

基　　金：supported by National "Eleventh Five-year" Project of China(Grant No.2009ZX03003-006-03);National Natural Science Foundation of China(Grant No.60902013)

摘　　要：In order to coherently detect the transmitted data symbols,an orthogonal frequency division multi-plexing （OFDM） receiver requires reliable identification and equalization of the experienced wireless multipath fading channels.The information of path delays plays an important role in the procedure of identification and equalization.The need for high data rates motivated the search for blind identification and equalization methods because they save bandwidth by avoiding the use of training sequences.In OFDM systems,multipath fading channels introduce interference between adjacent symbols which can be prevented by inserting a cyclic prefix （CP） before each symbol.In this paper,we find that the power of the interference in the CP interval can be estimated by using the circular convolution and based on the variations of the interference power,the time delay of each path can be estimated blindly.In order to coherently detect the transmitted data symbols,an orthogonal frequency division multi-plexing （OFDM） receiver requires reliable identification and equalization of the experienced wireless multipath fading channels.The information of path delays plays an important role in the procedure of identification and equalization.The need for high data rates motivated the search for blind identification and equalization methods because they save bandwidth by avoiding the use of training sequences.In OFDM systems,multipath fading channels introduce interference between adjacent symbols which can be prevented by inserting a cyclic prefix （CP） before each symbol.In this paper,we find that the power of the interference in the CP interval can be estimated by using the circular convolution and based on the variations of the interference power,the time delay of each path can be estimated blindly.

关 键 词：multipath delay cyclic prefix OFDM 

分 类 号：TN929.5[电子电信—通信与信息系统] TN929.533[电子电信—信息与通信工程]