北斗二号导航弱信号捕获算法研究

发布时间：2018-01-09 10:05

本文关键词：北斗二号导航弱信号捕获算法研究　出处：《重庆大学》2014年硕士论文　论文类型：学位论文

【摘要】：全球卫星导航技术（GNSS, Global Navigation Satellite System）由其应用领域之广泛，近些年来得到了快速的发展。我国自主研发搭建的北斗导航系统（BDS,Beidou System），更是由于其对我国国防事业的重要意义，受到了国内外的广泛关注和研究。2013年，中国卫星导航系统管理办公室对外公布了两个民用信号规范文件，标志着北斗二号导航系统（BD-2, Beidou-2System）将向民用领域进军。BD-2信号捕获性能的好坏直接影响系统定位的性能，卫星与用户间通讯的导航信号在传输过程中受多径衰落、阴影效应、噪声的影响，导致处于室内、建筑群、隧道等复杂环境下的用户捕获信号困难，为适应更为广泛的用户需求，研究具有更高灵敏度的BD-2导航信号的捕获算法势在必行。论文围绕BD-2导航弱信号捕获算法展开，主要研究内容如下：首先，对BD-2B1I/B2I路信号进行研究。给出BD-2B1I/B2I路信号的发射机结构，介绍BD-2B1I/B2I路信号的特点以及其测距码相关特性和频谱特性，给出BD-2导航电文的两种结构及其调制方式，并建立BD-2B1I/B2I路数字信号模型。其次，研究BD-2信号捕获算法的基本理论。给出BD-2接收机的结构，介绍常用的伪码捕获方法，，分析BD-2信号捕获的要素和捕获流程，完成基本的基于FFT时域并行捕获算法的仿真实验和性能分析，同时介绍了BD-2信号捕获算法的性能指标。接着，提出四类BD-2弱信号并行捕获算法。介绍影响导航信号传播的主要因素，分别提出相干累积并行捕获算法、相干—非相干累积并行捕获算法、相干—差分相干累积并行捕获算法以及克服导航数据比特翻转影响的最优半比特相干—非相干累积并行捕获算法，对各算法的原理和实现步骤进行详细的介绍，通过对各类算法的仿真实验得到各自的性能分析，并对这几类算法的捕获性能进行对比。最后，提出了一种基于差分判决的BD-2弱信号长比特相干捕获算法。介绍了算法的原理、实现流程、差分判决及相干累积过程。通过仿真实验和性能分析，将所提算法与一般的BD-2弱信号并行捕获算法进行对比，得出所提算法性能的优越性，最后总结出所提算法在弱信号捕获过程中的优势。
[Abstract]:Global Navigation Satellite System ( GNSS ) has been developed rapidly in recent years due to its wide application field . The Beier Navigation System ( BDS ) , which has been built by our country ' s independent research and development , has received extensive attention and research at home and abroad . In this paper , a weak signal acquisition algorithm based on BD - 2 navigation is developed . The main research contents are as follows : Firstly , the BD - 2B11 / B2I path signal is studied . The transmitter structure of BD - 2B11 / B2I path signal is given . The characteristics of BD - 2B11 / B2I path signal and its correlation characteristics and frequency spectrum characteristics are introduced . Two kinds of structure and modulation methods of BD - 2 navigation message are given , and a BD - 2B11 / B2I path digital signal model is established . Secondly , the basic theory of BD - 2 signal capture algorithm is studied . The structure of BD - 2 receiver is given , the common pseudo code acquisition method is introduced , the element and capture process of BD - 2 signal acquisition are analyzed , the simulation experiment and performance analysis of the basic FFT time domain parallel capture algorithm are completed , and the performance index of BD - 2 signal acquisition algorithm is also introduced . Next , four kinds of BD - 2 weak signal parallel capture algorithms are presented . The main factors that affect the propagation of navigation signals are introduced . The coherent accumulation parallel capture algorithm , the coherent - incoherent cumulative parallel capture algorithm , the coherent - differential coherent accumulation parallel capture algorithm and the optimal half - bit coherent - incoherent cumulative parallel capture algorithm that overcome the influence of the inversion of the navigation data bits are presented . The principle and realization steps of each algorithm are described in detail , and the performance analysis of each algorithm is obtained , and the capture performance of these algorithms is compared . Finally , a BD - 2 weak signal long - bit coherent acquisition algorithm based on differential decision is presented . The principle of the algorithm , the realization process , the difference judgement and the coherent accumulation process are introduced . Through the simulation experiment and the performance analysis , the proposed algorithm is compared with the general BD - 2 weak signal parallel capture algorithm , and the superiority of the proposed algorithm is obtained . Finally , the advantages of the proposed algorithm in the process of weak signal acquisition are summarized .

【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN96.1

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