载波加权正交频分复用系统的同步性能分析  

Analysis of synchronization performance of weighting orthogonal frequency division multiplexing systems

作　　者：卢照敢[1] 张太镒[1] 周亚同[1] 沈晓东[1] 

机构地区：[1]西安交通大学电子与信息工程学院,西安710049

出　　处：《高技术通讯》2007年第9期897-901,共5页Chinese High Technology Letters

基　　金：国家自然科学基金（40274019）资助项目.

摘　　要：针对正交频分复用系统盲同步方法中载波加权的选择具有一定盲目性的问题,通过分析载波加权分别与系统误码率和载频定时估计误差之间的关系,推导出了载频定时估计的罗-克拉美界,然后通过权衡同步精确性和系统误码率之间的关系确定最优的载波加权.理论分析表明,在不同载波加权下载频定时估计误差和系统误码率存在一定程度的交换关系,由此通过权衡系统误码率和载频定时估计误差之间的关系可确定最优的载波加权.基于802.11a系统的仿真实验进一步表明,不同载波加权下的载频同步误差和系统误码率都能与各自的理论分析结果很好地吻合,最优的载波加权也使载频同步误差和系统误码率接近于理论分析的最优值.Aiming at the blind selection of carrier weightings of carrier weighting-based blind synchronization approaches in orthogonal frequency division multiplexing （OFDM） systems, the Cramer-Rao bounds （CRB） for carrier and timing synchronization errors are derived by analysing the relation between system symbol error ratio and cartier timing error for given cartier weights. Furthermore, there existed trade-off between carrier timing error and system symbol error ratio （SER） for different carrier weights. Thus, the optimal carrier weights could be obtained by trade-off between system SER and carrier and timing synchronization errors. The simulation experiments of 802.11 a system configuration for different cartier weights showed that carrier synchronization errors and system SER approximated their theoretical analysis, respectively, and that the optimal carrier weights also made cartier synchronization errors and system SER achieve their theoretical optimal values.

关 键 词：正交频分复用(OFDM) 载波加权 罗-克拉美界(CRB) 载频定时同步 

分 类 号：TN92[电子电信—通信与信息系统]