BOC调制系统性能分析及码同步技术的研究

发布时间：2018-01-11 04:06

本文关键词：BOC调制系统性能分析及码同步技术的研究　出处：《哈尔滨工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：二进制偏移载波调制（BOC）以其特殊的裂谱特性，已经在新一代的全球卫星导航系统中得到了应用和推广，但是其特殊的自相关函数多峰的性质给伪码的精准同步带来了一定的影响。因此如何能够降低副峰对接收端的影响，使BOC优良的裂谱性能得到最大化的展现变得至关重要。本文首先介绍了基本BOC调制以及由此衍生出的MBOC、AltBOC调制的产生机理，以及对各种调制方式的统计特性进行分析，归纳总结出相应的特点，并分析了参数的选取、带限和均方根带宽对BOC调制系统性能的影响。基于这些理论基础，着重研究了BOC调制信号伪码的同步技术。在对现有的捕获方法研究的基础上，将现有的无模糊的捕获方法归纳总结并分成两类，即对频谱进行搬移滤波处理频谱重构技术和对自相关函数直接进行改造的捕获技术，，综合分析FOB算法、SOB算法、filtered算法、ASPeCT算法、SCPC算法以及OQCC算法的性能及优缺点。进而利用波形重构的思想，基于码并行捕获算法，推导设计出一种新的去模糊的捕获算法，并在模拟的卫星导航接收系统中，对新算法的捕获过程进行了仿真验证。随后，对经典的跟踪环路NELP、VNELP的原理及工作流程进行分析，发现与其花时间来纠正这些由自相关函数的多峰性带来的错误跟踪的情况，不如直接对环路进行改进以便直接达到无模糊的跟踪的目的。利用新算法对传统的NELP跟踪环路进行改进，以期使得新环路相关器输出曲线和BPSK调制的相关器输出曲线相类似，即仅含有一个过零点达到无模糊跟踪的目的，并研究了相关间隔对相关器输出曲线的影响。最后对跟踪误差进行分析，并与伪码跟踪的克拉美罗下限和贝叶斯下限进行了比较。
[Abstract]:Binary offset carrier modulation (BOC) has been applied and popularized in the new generation of global satellite navigation system due to its special crack spectrum characteristics. But its special multi-peak character of autocorrelation function has a certain influence on the precise synchronization of pseudo-codes, so how to reduce the influence of the sub-peak on the receiver. It is very important to maximize the crack spectrum properties of BOC. In this paper, we first introduce the basic BOC modulation and the generated mechanism of the BOC modulation, and analyze the statistical characteristics of various modulation methods. The characteristics of BOC modulation system are summarized, and the influence of parameter selection, band limit and root-mean-square bandwidth on the performance of BOC modulation system is analyzed. The synchronization technology of BOC modulation signal pseudo code is studied emphatically. On the basis of the research on the existing capture methods, the existing non-fuzzy capture methods are summarized and divided into two categories. That is to say, the spectrum reconstruction technology and the acquisition technology which can directly transform the autocorrelation function are used to remove and filter the spectrum, and the FOB algorithm is synthetically analyzed. The performance, advantages and disadvantages of ASPeCT algorithm and OQCC algorithm are discussed. Furthermore, the parallel acquisition algorithm is based on the idea of waveform reconstruction. A new de-fuzzy acquisition algorithm is derived and designed, and the acquisition process of the new algorithm is verified by simulation in the simulated satellite navigation receiving system. Then, the principle and workflow of the classical tracking loop NELPNLP are analyzed, and it is found that it takes time to correct the error tracking caused by the multi-peakness of autocorrelation function. It is better to improve the loop directly to achieve the goal of non-fuzzy tracking. The new algorithm is used to improve the traditional NELP tracking loop. It is expected that the output curve of the new loop correlator is similar to the output curve of the correlator modulated by BPSK, that is, the output curve of the new loop correlator has only one beyond 00:00 to achieve the goal of no fuzzy tracking. The influence of correlation interval on the output curve of correlator is studied. Finally, the tracking error is analyzed and compared with Clemero lower bound and Bayesian lower bound of pseudo code tracking.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN96.1

【参考文献】