无线OFDM系统广义信道分析和自适应盲信道估计算法  

Analysis of the generalized channel of the wireless OFDM system and blind adaptive channel estimation algorithm for the OFDM system

作　　者：李峰[1] 李建东[1] 李夏[1] 

机构地区：[1]西安电子科技大学综合业务网国家重点实验室,陕西西安710071

出　　处：《西安电子科技大学学报》2003年第2期191-196,共6页Journal of Xidian University

基　　金：国家自然科学基金资助项目(69872028);"863"计划重大课题资助(2001AA123031);高等学校优秀青年教师教学科研奖励计划资助项目;教育部科学技术研究重点资助项目;高校骨干教师资助计划资助项目

摘　　要：将OFDM系统接收端的FFT看成是广义信道的一部分,对无线OFDM系统多径环境下的广义信道进行了理论分析,证明了无线OFDM系统多径环境下广义信道子信道输出和其非线性估计输出之间服从Bussgang过程.在此基础上得到了自适应LMS Bussgang盲信道估计算法,并提出了加快算法收敛和防止误差传播的方法.避免了信号相关检测时,周期重发导频信号带来的有效传输速率降低和传输时延.结果证明该算法是稳健、低复杂度、次最优的.A theoretic analysis is made of the generalized channel of a wireless OFDM system, in which the FFT of the OFDM receiver is considered as a part of the generalized channel. It is proved that the output of the subchannel of the wireless OFDM system generalized channel and its nonlinear estimation are subject to the Bussgang procedure. Thus, a blind adaptive algorithm, LMSBussgang, is proposed for blind channel estimation. Meanwhile, a novel amelioration scheme is presented for accelerating the convergence of the algorithm and preventing error propagation, thus avoiding the degradation of efficient transmission rate and transmission delay due to periodical retransmission of pilot signal in systems with coherent detection. Both theoretic derivation and simulation results show that the algorithm is robust, less complex, and suboptimal.

关 键 词：OFDM 自适应盲信道 正交频分复用 Bussgang过程 盲信道识别 分组间干扰 码间干扰 载波间干扰 无线通信 

分 类 号：TN92[电子电信—通信与信息系统]