基于TDOA的无线定位方法及其性能分析  

TDOA-based wireless positioning method and its performance

作　　者：史小红[1] 

机构地区：[1]东南大学信息科学与工程学院,南京210096

出　　处：《东南大学学报（自然科学版）》2013年第2期252-257,共6页Journal of Southeast University：Natural Science Edition

基　　金：江苏省产学研前瞻性研究基金资助项目(BY2009149)

摘　　要：为提高基于TDOA的无线定位系统的定位性能,建立了使用复数扩频调制信号、考虑频偏和多径因素的TDOA定位系统模型,推导了发送节点和接收机之间的无线信号传输表达式,揭示了频偏和多径对信号传输的影响.研究表明,针对Zigbee信号目标进行定位时,收发频偏对时间差影响较大,而在视距情况下多径对时间差的影响较小.在此基础上,提出了通过频偏估计校正接收机频偏的方法,以及通过已有的多天线选择接收方法克服由于多径产生的信号严重衰落问题.最后,用实际开发的定位系统进行了实验,结果表明,提出的基于TDOA的无线定位方案可将定位误差控制在5%以内,优于已有的基于TDOA的短距离无线定位方案.To improve the performance of time difference of arrival （TDOA） -based wireless positio- ning systems, a system model is established. This model employs complex spreading spectrum mod- ulated signal as transmitted baseband signal and takes into account factors of carrier frequency devia- tion and multipath effect. An expression of signal transmission between the transmitter and the re- ceiver is given. This expression indicates the influence of the frequency deviation and the multipath on wireless transmission. Research results show that, when aiming at Zigbee terminal targets, the frequency deviation has serious effect on the detection accuracy of the time of arrival （ TOA）, while the multipath causes just a little bias of TOA in conditions of line of sight （LOS）. Furthermore, methods to correct the frequency deviation and to overcome the serious fading due to multipath by use of multiple receiving antennas are proposed. Finally, positioning experiments are performed with the developed system. The results show that the proposed positioning method can reach a high per- formance with a positioning error less than 5 % in indoor environments, which is better than that of existing TDOA-based short distance wireless positioning systems.

关 键 词：无线定位 TDOA ZIGBEE 误差分析 高精度定位 

分 类 号：TN98[电子电信—信息与通信工程]