BOC调制信号多径抑制技术性能分析与改进

发布时间：2018-06-10 02:36

本文选题：全球卫星导航系统 + 多径抑制技术　；参考：《华中科技大学》2014年硕士论文

【摘要】：随着全球导航卫星系统（GNSS）现代化程度的提高以及导航信号接收技术的发展，热噪声等因素引起的随机误差已经得到了较好的消除，多径信号造成的误差已经成为GNSS高精度接收机的主要误差来源。因此，，如何减小多径对导航测距所带来的影响对提高接收机的定位精度具有重要的意义。目前二进制偏移载波（BinaryOffset Carrier，BOC）调制方式在导航系统广泛应用，而使用传统二进制相位偏移(Binary Phase Shift Keying，BPSK)信号的多径抑制技术，并不能在BOC信号上达到良好的多径抑制效果，因此，BOC调制信号多径抑制技术的研究就显得尤为重要。本文分析了多径信号特点及其对导航测距的影响，针对BOC调制方式分析了四种典型的多径抑制技术，包括窄相关技术、Double delta相关器技术、基于互相关函数的多径抑制技术、门函数多径抑制技术。首先分别研究了它们的基本原理和实现方式，然后通过软件进行数值仿真，分析了相关器间隔、码片宽度等参数对其多径性能的影响，并将四种技术进行了对比，对比结果表明四种技术中门函数多径抑制技术具有最好的多径抑制效果。此外，本文设计了一种可变幅度比的二进制对称Strobe波形，在改变波形正负电平比值获得良好的跟踪性能和多径抑制性能的前提下，能够保证跟踪环牵引范围不变。首先介绍了该码片波形具体形式，对本地参考信号的构成方式进行了说明，并推导得到了多径误差包络的解析表达式。然后通过数值仿真对多径误差包络表达式进行了验证，分析了使用不同正负电平幅度比Strobe波形对多径抑制技术的码跟踪性能和多径抑制性能的影响。
[Abstract]:With the improvement of GNSS modernization and the development of navigation signal receiving technology, the random error caused by thermal noise has been eliminated. The error caused by multipath signal has become the main error source of GNSS high precision receiver. Therefore, how to reduce the influence of multipath on navigation ranging is of great significance to improve the positioning accuracy of the receiver. At present, binary offset Carrier Carrier (BOC) modulation is widely used in navigation system, but the multipath suppression technique of binary Phase shift Keying BPSK signal can not achieve good multipath suppression effect on BOC signal. Therefore, it is very important to study the multipath suppression technology of BOC modulation signal. This paper analyzes the characteristics of multipath signal and its influence on navigation and ranging, and analyzes four typical multipath suppression techniques for BOC modulation. It includes narrow correlation technique, double delta correlator technique, multipath suppression technique based on cross-correlation function and gate function multipath suppression technique. In this paper, the basic principle and realization method are studied, and then the effects of correlator interval, chip width and other parameters on multipath performance are analyzed by numerical simulation, and the four techniques are compared. The comparison results show that the gate function multipath suppression technique has the best multipath suppression effect. In addition, a binary symmetric Strobe waveform with variable amplitude ratio is designed. On the premise of changing the positive and negative level ratio of the waveform to obtain good tracking performance and multipath suppression performance, the traction range of the tracking loop can be kept unchanged. Firstly, the concrete form of the chip waveform is introduced, the structure of the local reference signal is explained, and the analytical expression of the multipath error envelope is derived. Then the multipath error envelope expression is verified by numerical simulation, and the influence of Strobe waveform on code tracking performance and multipath suppression performance of multipath suppression technique is analyzed by using different positive and negative level ratio Strobe waveforms.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN911.3;TN96.1

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