无线弥散信道下OFDM系统中时间同步方案的比较分析  

A Comparative Analysis on Time Synchronization Schemes in OFDM Systems Based Upon Dispersive Cannel Model

作　　者：邝育军[1] 侯晓林[1] 乐光新[1] 

机构地区：[1]北京邮电大学电信工程学院,北京100876

出　　处：《北京邮电大学学报》2003年第3期75-80,共6页Journal of Beijing University of Posts and Telecommunications

基　　金：国家自然科学基金资助项目(60172052);国家自然科学基金重大研究计划资助项目(90104018);"十五"863重大研究课题资助项目(2001AA123016)

摘　　要：首次直接在弥散信道上讨论OFDM系统的时间同步模型,并在此基础上分析了OFDM通信系统中的基于训练序列和基于循环前缀的两类时间同步技术的在不同信噪比条件和不同信道冲激响应长度下的同步性能.Time synchronization of OFDM systems is analyzed directly upon practical channel modeldispersive channel model. Two typical time synchronization and framestart detecting schemes are surveyed. Theoretical analysis and simulation results suggest that, time and frequency estimators based on only cyclic prefix (CP) are far inferior to those based upon pilot symbols. Simulation results also suggest that performance of CP based methods cannot be improved by increasing signaltonoise ratio (SNR). Hence, appropriately designed pilots are highly necessary for both time and frequency synchronization.

关 键 词：正交频分复用 时间同步 循环前缀 OFDM 弥散信道 比较分析 信噪比 

分 类 号：TN911.23[电子电信—通信与信息系统]