基于BEM模型的LOFDM系统双散射信道最大多普勒扩展F范数估计  

F-norm-based Maximum Doppler Spread Estimation via BEM Model for LOFDM Systems in Doubly-dispersive Channels

作　　者：黄福贵 黄丽波[2] 高猛[3] 袁晓勇[4] 

机构地区：[1]海军驻景德镇地区航空军事代表室 [2]中国人民解放军92524部队 [3]解放军理工大学通信工程学院研究生2队 [4]中国人民解放军96550部队

出　　处：《军事通信技术》2011年第4期18-24,56,共8页Journal of Military Communications Technology

摘　　要：最大多普勒扩展作为信道时变性的直接反映,是网格正交频分复用LOFDM(Lattice Orthogonal Frequency Division Multiplexing)系统自适应策略的重要参数之一。准确的最大多普勒扩展估计对于LOFDM系统发送端信号设计以及自适应策略实现十分重要。文章针对LOFDM系统的特殊信号结构以及双散射信道的快时变特性,采用DFT-BEM信道模型近似快时变信道响应,结合快时变信道下LOFDM系统块传输接收方案,利用梳状导频辅助估计多普勒域平均信道频率响应,在此基础上利用信道响应估计值的时间相关函数提出了基于F范数的信道最大多普勒扩展估计算法。理论分析与计算机仿真表明提出的估计算法具有良好的均方误差性能和收敛性能。The maximum Doppler spread,or equivalently,the mobile speed,is a measure of the spectral dispersion of the mobile fading channel.Accurate estimation of the mobile speed is of importance in Lattice Orthogonal Frequency Division Multiplexing（LOFDM） systems which require knowledge of the rate of channel variations to achieve its transmission signal design and adaptive strategy.Aiming at the special structure of LOFDM signals and fast time-varying characteristics of doubly-dispersive channels,the Discrete Fourier Transform based Basis Expansion Models（DFT-BEM） was used to approach the real fast time-varying channel,and the Doppler domain averaging channel Frequency Response（CFR） was estimated by exploiting the comb-type pilots and the block transmission strategy.Based on the time auto-correlation function of the CFR estimated value,the F-norm based maximum Doppler spread estimation algorithm was proposed. Theoretic analysis and simulation results demonstrate that the proposed algorithm has good Mean Square Error（MSE） performance,while the convergence performance is sound.

关 键 词：网格正交频分复用系统 基扩展 双散射信道 最大多普勒扩展估计 

分 类 号：TN929.5[电子电信—通信与信息系统]