卫星导航新体制信号的抗多径环路跟踪技术研究

发布时间：2018-01-13 17:46

本文关键词：卫星导航新体制信号的抗多径环路跟踪技术研究　出处：《北京理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：为实现频谱共享和提升系统性能，各国都先后提出了卫星导航系统的现代化方案。BOC调制作为一种新的信号调制方式，在现代化方案中被多个国家的卫星导航系统广泛使用，从而产生了BOC信号及它新的变种信号。这些信号在给系统带来一系列性能提升的同时，也对信号的抗多径算法能够达到的抗多径性能提出了更高的要求。本课题研究目的是设计实现新体制卫星导航信号的抗多径环路跟踪技术，得出一种最适合新体制信号的抗多径算法。本文首先对新体制信号的调制方式进行了介绍，从信号的产生方式、自相关函数和功率谱密度三个方面作了研究；又简单介绍了BOC调制信号的跟踪算法，给出了几种典型的针对新体制卫星导航信号的跟踪算法；接着本文对多径现象的特征进行了分析，通过对多径模型的研究，明确了多径干扰对延迟锁定环路和载波跟踪环的影响。本文重点论述了三种基于码跟踪环的抗多径技术（窄相关、Double-Delta和MEDLL）的原理，并比较了它们的抗多径性能。并在MATLAB上仿真实现了三种算法，通过对三种算法多径误差包络图的分析和研究，，得出在码跟踪环路上增加相关器的个数，可有效提高直达信号时延估计精度，但同时会降低处理速度，所以需在成本与精度之间折中选择。同时，通过比较三种抗多径技术，说明MEDLL算法有更好的抗多径性能，能基本消除多径产生的码跟踪误差。最后，本文详细介绍了MEDLL算法流程图，分析了MEDLL算法如何估计多径参数（相位估计、时延估计、幅度估计）及进行循环迭代。给出了新体制信号中抗多径MEDLL算法的软件实现框图。
[Abstract]:In order to realize spectrum sharing and improve the system performance, every country has put forward the scheme of modern satellite navigation system.BOC modulation is a new modulation method, is widely used in satellite navigation system in a number of countries in the modernization program, resulting in a new variant of BOC signal and its signal. These signals in a boost a series of performance at the same time to the system, but also put forward higher requirements to the anti multipath performance of anti multipath signal. This algorithm can achieve the purpose of the research is to design the anti multipath loop tracking technology new system of satellite navigation signals, and presents a new system for the signal of the anti multipath algorithm.
This paper first modulation signal of the new system are introduced, generated from the signal, autocorrelation function and power spectral density are studied in three aspects; and briefly introduces the tracking algorithm of BOC modulated signal, the tracking algorithm is given for several typical new system of satellite navigation signal; then the characteristics of the the multipath phenomenon is analyzed through the research of the multipath model, the effect of multipath interference on the delay locked loop and carrier tracking loop.
This paper focuses on the three kinds of anti multipath technology based on code tracking loop (narrow, Double-Delta and MEDLL) principle, and compared the anti multipath performance of them. And in the MATLAB simulation of the three algorithms, through analysis and Research on three kinds of multipath error envelope algorithm, obtained a number of related device the increase in the code tracking loop, which can effectively improve the direct signal delay estimation accuracy, but also reduces the processing speed, so the need to compromise between cost and accuracy. At the same time, through the comparison of three kinds of anti multipath techniques, MEDLL algorithm has better anti multipath performance, can basically eliminate the code tracking error generated by multipath.
Finally, this paper introduces the flow chart of MEDLL algorithm in detail, and analyzes how to estimate multipath parameters (phase estimation, time delay estimation, amplitude estimation) and cyclic iteration by MEDLL algorithm. It also gives the block diagram of software implementation of anti multipath MEDLL algorithm in new system.

【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN96.1

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