北斗BOC信号捕获算法研究
摘要GPS现代化以及Galileo系统都将使用BOC调制信号,与单纯的扩频码相比,BOC信号有更小的跟踪抖动和更好的抗多径性能,但因为BOC信号自相关函数具有多峰性,使得捕获更具挑战性,跟踪时容易锁在假峰上。为了快速，准确的对卫星导航信号实施捕获，本文围绕BOC调制信号的捕获算法展开研究。首先针对BOC调制技术展开研究，分析了BOC调制信号的自相关特性，频谱特性和模糊特性；然后在介绍了软件接收机基本捕获算法原理的基础上，对互相关、副载波消除、三路并行相关及边带处理四种BOC调制信号捕获算法进行了研究分析，通过性能比较选取改进的互相关算法作为消除BOC调制信号多峰值特性，实现信号快速捕获的算法。仿真结果表明，在正负1/2个码片的误差范围内，该算法能够成功捕获BOC调制信号。64495
毕业论文关键词 BOC调制 多峰值 自相关 频谱 模糊性 互相关算法
毕业设计说明书（论文）外文摘要
Title Beidou BOC Signal Acquisition Algorithm Research
Abstract BOC modulation will be used in GPS modernization and Galileo Navigation Satellite System. This modulated signal induces better tracking in white noise and better inherent multipath mitigation compared to the spreading code alone. However, it also makes acquisition more challenging and tracking potentially ambiguous due to its multiple peak autocorrelation function. In order to acquire the satellite navigation signal quickly and
accurately, the paper research on the acquisition algorithm of BOC modulated signal. Firstly, developing research on the BOC modulation techniques and analyzing the autocorrelation features,spectral features and unique fuzzy features of BOC modulated signal.Then on the basement of the introduction of the basic software receiver acquisition algorithm principle,analysis the cross-correlation algorithm、the elimination of the subcarrier algorithm、Three parallel related road algorithm and the webbing handle algorithm. By comparing the performance,selected the improved cross-correlation algorithm as the basement algorithm of what eliminate multi-peak feature and make a fast acquisition of BOC modulated signal. Simulation results show that within the scope of error of plus or minus 1/2 yards, the algorithm can accurately capture the signal.
Keywords BOC modulation multiple peak autocorrelation spectral fuzzy features cross-correlation algorithm
1 绪论 1
1．1 GNSS发展概况 1
1．2 课题研究的背景，目的和意义 4
1．4 论文内容安排 5
2 扩频通信基本原理 6
2．1 扩频通信的理论基础 6
2．2 扩频通信系统的组成结构和基本概念 6
3 BOC调制信号 9
3．1 BOC信号调制原理 9
3．2 信号采样频率的选取 16
3．3 BOC信号的模糊性分析 17
4 BOC调制信号捕获算法研究 18
4．1 GPS信号捕获算法 18
4．2 BOC调制信号捕获算法 23
4．3 各种算法的比较