GPS软件接收机中信号捕获、跟踪算法的研究与实现

发布时间：2018-04-01 19:40

本文选题：GPS　切入点：软件接收机　出处：《北京邮电大学》2013年硕士论文

【摘要】：目前,全球定位系统GPS(Global Position System)接收机中算法的研究正随着全球定位系统(GPS)的飞速发展而受到业界越来越多的关注。基于软件无线电的GPS接收机软件化的实现,以其可编程、易修改、模块化、对算法适应性强、可扩展性优等特点,成为近些年卫星导航领域的研究热点。而捕获、跟踪、PVT(Position Velocity Time)解算等算法作为软件接收机中的关键技术,对软件接收机的性能起着至关重要的作用。通过对这些关键算法的研究,可以为我国自主研制的北斗导航接收机提供参考和借鉴。文中重点对GPS软件接收机中捕获、跟踪的相关算法进行了研究。首先,文章介绍了构成GPS系统的各个部分以及它们之间的工作方式；其次就GPS信号的构成、调制方式、信号特性以及信号源设计进行了详细的阐述,在matlab/simulink平台上实现各参数可控的GPS信号源的建模与仿真,以便利用该信号源对捕获、跟踪算法进行验证；然后分析了GPS接收机的基本工作原理,具体剖析了GPS信号的捕获、跟踪算法的原理；接着对常用的捕获和跟踪的算法进行了研究。提出时域频率双并行捕获算法,该算法在频移上利用并行频率搜索法对多普勒频移进行一次性搜索,在时域上利用多相关器对C/A码相位偏移进行多点搜索,通过双并行的方式减少搜索单元的数量,从而提高搜索捕获速度；同时,在捕获判决策略上提出变长-定长联合检测法的捕获搜索判决策略,该策略以变长时间搜索法为主,固定时间搜索法为辅,在有效节约搜索时间的同时,避免搜索进入死循环,有效的节约了特殊情况下的捕获搜索时间；然后在matlab/simulink平台上完成算法的建模和仿真,验证算法的可行性和可靠性；最后,结合面向对象编程的思想,使用C++语言实现一个软件接收机。
[Abstract]:At present, the research of algorithms in GPS(Global Position system receiver is getting more and more attention with the rapid development of GPS. The realization of GPS receiver based on software radio is programmable. Easy to modify, modularization, strong adaptability to algorithm, excellent scalability and other characteristics, it has become a research hotspot in the field of satellite navigation in recent years. As the key technology of software receiver, acquisition, tracking, position Velocity time algorithm and other algorithms are the key technologies. It plays an important role in the performance of the software receiver. Through the research of these key algorithms, it can provide reference and reference for the Beidou navigation receiver which is developed independently in our country. This paper focuses on the acquisition and tracking algorithms in the GPS software receiver. Firstly, this paper introduces the components of the GPS system and how to work between them. Secondly, the structure and modulation of the GPS signal are introduced. The characteristics of the signal and the design of the signal source are described in detail. The modeling and simulation of the GPS signal source with controllable parameters are realized on the matlab/simulink platform, so that the acquisition and tracking algorithm can be verified by the signal source. Then the basic working principle of GPS receiver is analyzed, the principle of GPS signal acquisition and tracking algorithm is analyzed in detail, and then the common algorithms of acquisition and tracking are studied. The algorithm uses parallel frequency search method to search the Doppler frequency shift in time domain, and uses multiple correlators to search the phase shift of C / A code in time domain, and reduces the number of search units by double parallel method. In order to improve the speed of search and acquisition, at the same time, in the acquisition decision strategy, a new strategy of variable length and fixed length joint detection is proposed, which is mainly based on the variable time search method, supplemented by the fixed time search method. At the same time to save the search time effectively, avoid the search into a dead cycle, effectively save the acquisition search time under special circumstances; then complete the algorithm modeling and simulation on the matlab/simulink platform, verify the feasibility and reliability of the algorithm; finally, Combined with the idea of object-oriented programming, C language is used to implement a software receiver.
【学位授予单位】：北京邮电大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P228.4

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