文档介绍：上海交通大学硕士学位论文蜂窝无线定位系统的精确定位算法研究姓名:吴佳栋申请学位级别:硕士专业:电路与系统指导教师:朱杰20090201上海交通大学硕士学位论文摘要i 摘要蜂窝无线定位系统随着通信技术的大规模发展已成为越来越活跃的研究领域,在理论和应用方面都涌现了大量的研究成果。信号到达时间差(TDOA)定位法是蜂窝无线定位技术中应用最广泛的定位方法,与之相关的参数估计和定位算法也是国内外研究者关注的热点课题。 本文围绕信号到达时间差(TDOA)方法,做了如下四个方面的工作: 1. 以满足大型城市地面定位服务为出发点,探讨了定位系统的构建框架。研究了作为定位系统基础的直序扩频通信系统的相关特性。并根据定为算法的特点和需求,对普通的直括系统进行了改进,使之能更好的承载精确定位服务。 2. 从最基本的白噪声序列开始,分析了不同定位信号序列在本系统中的性能。给出了如何选择最优的定位信号序列的标准和方法。 3. 本文重点研究了TDOA 参数估计的几种主要方法,对广义互相关方法的原理,以及在直接和间接TDOA 估计中的性能进行了仿真,并且对算法做了进一步的优化。同时,还分析了多径效应对TDOA 估计精度的影响,尝试性的研究了超分辨率方法辅助的相关算法在抵抗多径效应中的性能。 4. 详细研究了基于TDOA 参数的多种双曲定位算法,包括直接求解、最小二乘估计算法、Chan 算法、近似极大似然估计算法。详细的推导各种算法求解三维位置估计的过程,并且对各种算法的性能进行了分析。最后,综合各部分的研究做了总结,并对将来的工作进行了展望。关键词: 蜂窝无线定位,到达时间差定位法,直序扩频通信,广义互相关,超分辨率,近似极大似然估计上海交通大学硕士学位论文 ABSTRACT ii ABSTRACT With the rapid advancement of munication technology, Cellular Location System has e a very hot researching field. Lots of achievements are plished these years in laboratories as well as in real life application. With in several kinds of location techniques, Time Difference of Arrival (TDOA) based method would be the most widely used one in location system. So far, TDOA method and its relating estimation technologies have drawn more and more attention. This paper mainly investigates four important aspects in realization of a TDOA based cellular location system. order to fulfill the location service need of a metropolis, the framework design of a cellular location system is provided. Thefundamental direct sequence spectrum spread system, which sustains the location technology, and the improvements of such system are studied. from the basic white noise sequence, the paper evaluated the performance of different location signal sequences, and introduced how to generate a sequence suitable for location application. paper studied several algorithms in TDOA estimation. Emphasis has been placed at General Cross Correlation method. Si