摘要信号的跟踪是在信号的捕获基础上对信号进行进一步的处理,实现信号的伪码剥离和载波剥离,得到初步的数据比特。只有准确的跟踪到信号,才能对信号进行进一步的处理,从而得到想要的数据。论文的主要内容有:65212
首先分析了GPS信号与BOC信号的的生成流程,比较BOC信号与GPS信号之间的区别。其次对所生产的信号进行捕获,采用并行码相位搜索。它实际上利用傅里叶变换这种数字信号处理技术来代替数字相关器的相关运算。再次在捕获的基础上,对信号进行跟踪。码环鉴别器的鉴相方法采用的是非相干超前减滞后幅值法。载波环采用的是叉积鉴频器。最后为了消除BOC信号的相关函数存在多峰造成的跟踪模糊问题,对码环进行部分的修改,消除相关函数的旁瓣,从而能使跟踪环路正确锁定。
结论:用改进的环路跟踪CBOC信号,通过仿真,能够初步实现对信号的跟踪。
毕业论文关键词:BOC信号;自相关性;并行码相位搜索;叉积鉴频器;信号跟踪回路
毕业设计说明书(论文)外文摘要
Title Beidou BOC signal tracking algorithm
Abstract
Signal tracking based on the captured signal is to realization of signal code stripping and carrier removal, obtained preliminary data bits. Only accurate tracking of the signal, the signal can be further processed to obtain the desired data. The main thesis work:
Analysis the generation process of the GPS signal and the BOC signal, and comparing the difference between the GPS signal and the BOC signal. To capture the signal produced using the parallel code phase search. It is actually the Fourier transform of this digital signal processing technology to replace the digital correlator correlation operation. On the basis of the capture, it will be tracking for the signal. Code loop discriminator phase method uses a non-coherent advance minus hysteresis amplitude method. Carrier ring is used in a frequency discriminator of cross product. In order to eliminate the presence of a BOC signal correlation function multimodal ambiguity caused by tracking, the code ring part of the changes, to eliminate sidelobe correlation function, thereby enabling the tracking loop is properly locked.
Conclusion: With the improvement of the tracking loop of CBOC signal, through simulation, can realize the signal tracking.
Key words:BOC signal,Autocorrelation,Parallel code phase search ,Cross product discriminator,Signal tracking loop
目 录
1 绪论 1
1.1 课题的背景及来源 1
1.2 我国卫星导航系统的概况 3
1.3 课题研究的内容及意义 4
2 BOC信号的生成 5
2.1 GPS信号的生成 5
2.2 BOC信号的生成 6
2.3 CBOC(6,1,1/11) 信号的生成 7
2.4 BOC(1,1),BOC(6,1)和CBOC(6,1,1/11)的功率谱 11
2.5 本章小结 14
3 BOC信号的捕获 14
3.1 BOC信号的捕获原理 14
3.2 伪码的生成 14
3.3 FFT捕获原理 16
3.4 本章小结 20
4 BOC信号的跟踪