基于ZigBee的LS频偏估计改进算法  

A Modified Algorithm of LS Frequency Offset Estimation Based on ZigBee

作　　者：刘述钢[1] 刘宏立[1] 王彦[1] 

机构地区：[1]湖南大学电气与信息工程学院,湖南长沙410082

出　　处：《信息与控制》2011年第4期472-476,共5页Information and Control

基　　金：国家863计划资助项目(2007AA11A121);湖南省科技厅计划资助项目(2008FJ3114)

摘　　要：针对无线信道的多径干扰特性,本文对基于最小平方(LS)误差准则的数据辅助式频偏估计算法进行改进,提出一种根据训练序列或前导符的相关性进行频率偏移估计的改进算法.在ZigBee协议条件下的仿真结果表明该改进算法的均方误差优于BAF(best angular fit)算法的均方误差.当信噪比(SNR)大于9 dB时,该算法的频偏估算精度接近于粗略频偏估计与精细频偏估计相结合的估计算法,其估算均方差接近克拉美—劳下界(CRLB).因此,在大城市无线信道环境下,该算法能满足基于ZigBee技术的无线自动抄表的通信要求.For multi-path interference characteristics of wireless channel,the data-aided frequency offset estimation al-gorithm is improved based on the least squares（LS） error criterion.And a modified algorithm is proposed according to the correlation of the training sequence or the preamble symbols.The simulation results under specifications of ZigBee show that the mean square error（MSE） of the modified algorithm is better than that of the BAF（best angular fit） algorithm.When SNR is greater than 9 dB,the accuracy of frequency offset estimation of the algorithm comes up to the accuracy of the com-bination algorithm of coarse frequency estimation and fine frequency estimation.At the same time,the MSE of the proposed algorithm is close to Cramer-Rao low boundary（CRLB）.Therefore,the algorithm can meet communication requirements for automatic meter reading system based on Zigbee technology in the metropolitan wireless channel environment.

关 键 词：频偏估计 多径干扰 无线传感网络 克拉美—劳下界 

分 类 号：TN91[电子电信—通信与信息系统] TP33[电子电信—信息与通信工程]