突发OFDM系统的精确定时估计及性能仿真

Robust Timing Offset Estimation Scheme for Burst OFDM Systemsand Performances Simulations

首先从理论上分析了载波频偏对基于互相关的精确定时估计算法性能的影响,然后提出一种对频偏不敏感且与训练符号结构无关的精确定时算法,并利用仿真分析了不同信道条件下定时测度函数在精确定时位置的均值、方差分布特性。将该算法应用于IEEE 802.16d系统中进行仿真,结果表明该算法能够克服载波频偏影响,且定时精度高。

The effects of carrier frequency offset on cross-correlation based timing algorithm were analyzed theoretically and an improved timing algorithm was proposed.The new method was neither sensitive to frequency offset nor dependable on the concrete preamble structure.Then,the distribution performances of the expectations and variances of the newly proposed timing metric were analyzed over different wireless channels through Monte-Carlo simulations.The algorithm was applied in IEEE 802.16d system and simulations were carried out.The simulation results show that the new method is less sensitive to frequency offset,and the timing effect is very accurate.