OFDM系统有限字符集特性的盲信道估计  

Finite-Alphabet Based Blind Channel Estimation for OFDM Systems

作　　者：居敏[1] 许宗泽[1] 

机构地区：[1]南京航空航天大学信息科学与技术学院,江苏南京210016

出　　处：《应用科学学报》2008年第5期441-447,共7页Journal of Applied Sciences

基　　金：国家自然科学基金资助项目(No.60572108)

摘　　要：提出并证明了正交频分复用(OFDM)系统中基于信息符号有限字符集特性的信道盲可辨识的充分必要条件.在满足该条件的前提下,又提出一种频域最小距离(frequency-domain minimum distance,FMD)盲信道估计方法.该方法将信道频率响应序列多相分解为若干子向量,通过对其中一个子向量中元素的相位模糊度进行穷尽搜索,辨识出所有子载波上频率响应的相位.仿真结果表明,FMD算法的信道估计性能优于修正的最小距离(modifiedminimum distance,MMD)算法,而计算复杂度与MMD相等.For OFDM systems, necessary and sufficient conditions for blind channel identifiability based on the finite alphabet property of information symbols are established. Under these conditions, a novel frequency-domain minimum distance （FMD） algorithm is proposed for blind channel estimation. By polyphase decomposition, the channel frequency response sequence is divided into several subsequences, and phase ambiguities of each subcarrier can be resolved by exhaustive searching only （ L ＋ 1 ） elements in one subsequence, where L is the channel order. Simulation results show that the channel estimation accuracy of the FMD algorithm is better than the modified minimum distance （MMD） algorithm, both having the same computation complexity.

关 键 词：正交频分复用 盲信道估计 有限字符集特性 多相分解 

分 类 号：TN911.23[电子电信—通信与信息系统]