GNSS空间信号干扰评估及抑制方法研究

发布时间：2018-03-04 18:10

本文选题：GNSS信号　切入点：性能评估　出处：《中国科学院研究生院（国家授时中心）》2014年博士论文　论文类型：学位论文

【摘要】：全球卫星导航系统GNSS（Global Navigation Satellite System）最初的研制目标是为了给用户提供全天候、全球性、高精度的位置信息，但是由于卫星信号自身所具有的特性，无论是GPS、GALILEO、 GLONASS还是北斗卫星导航系统，都存在着一个共同的缺点——容易受到各种形式的有意或者无意的干扰，从而导致用户接收机的定位、导航性能下降，甚至无法正常工作。目前空间环境愈加复杂，存在各种自然干扰及人为干扰，接收机的抗干扰能力已经成为其能否正常工作的一个关键问题。分析GNSS导航信号在干扰环境下的接收性能，并提出有效可行的抗干扰方法，对于提高卫星导航系统在复杂环境下的工作性能、增强其在各种环境中的适用性具有重要意义。本论文正是针对目前卫星导航所处的复杂电磁环境和有限的抗干扰能力问题，对GNSS信号在干扰环境下接收性能的评估方法进行了系统得研究，并针对几种常见的干扰形式，有针对性的提出相应的干扰抑制方法，从而提高卫星导航系统的抗干扰能力。本论文的主要研究内容也是紧密围绕着干扰环境下导航信号接收性能评估方法研究和干扰抑制方法研究两个方面。本文首先对GNSS空间信号在干扰环境下接收性能的评估方法进行了系统研究，通过对接收信号的频域性能、捕获性能、跟踪性能、解调性能等各个角度进行分析，综合反映导航接收机在干扰环境下的接收性能。针对目前国际上普遍关注的GNSS信号间干扰的评估，提出了一种不同于目前国际上现有方法的可直接对干扰进行评估的新方法，即利用干扰因子k~ jam作为信号间干扰的评估参数，越大，则干扰越大，接收性能随之越差。该方法可以简单准确的评估信号间干扰的大小。同时本文还对高斯白噪声环境下的接收性能以及其它干扰环境下的接收性能进行了细致的分析和研究，全面的评估各种干扰对GNSS信号的影响。其次，本文对不同干扰的抑制方法进行了研究。对于常见的窄带干扰形式，通过LMS线性预测技术将窄带干扰可以有效去除，从而提高接收信号的抗干扰能力。而对于宽带干扰，，用一般的时域或频域抑制方法对其干扰的抑制效果不佳，因此宽带干扰的抑制是本文的一个重点。本文着重对线性调频宽带干扰和正弦调频宽带干扰展开了深入研究，针对每种干扰分别给出了两种干扰抑制的实现方法，并通过仿真结果给出每种干扰抑制方法的适用条件。最后，为了验证本文提出的GNSS信号接收性能的评估方法和干扰抑制方法的正确性，本文设计了一个实验验证平台。基于该实验平台，采集实测的GNSS卫星导航信号并叠加不同类型的干扰，然后利用本文提出的干扰抑制方法对干扰进行抑制，通过分析GNSS信号的接收性能在干扰抑制前后的变化和改善，从而验证本文提出的干扰抑制方法的可行性和有效性。
[Abstract]:GNSS(Global Navigation Satellite system was originally developed to provide users with all-weather, global and high-precision position information. However, due to the characteristics of satellite signals themselves, whether it is GPS / GALILEO, GLONASS or Beidou satellite navigation system, They all have a common drawback-they are vulnerable to various forms of intentional or unintentional interference, which leads to the positioning of user receivers, the deterioration of navigation performance, or even failure to work properly. The space environment is becoming more complex. There are various kinds of natural interference and artificial interference, and the anti-jamming ability of the receiver has become a key problem whether the receiver can work normally. This paper analyzes the receiving performance of the GNSS navigation signal in the jamming environment, and puts forward an effective and feasible anti-jamming method. It is of great significance to improve the performance of satellite navigation system in complex environment and enhance its applicability in various environments. In this paper, aiming at the problem of complex electromagnetic environment and limited anti-jamming ability of satellite navigation at present, the evaluation methods of receiving performance of GNSS signal in jamming environment are systematically studied, and several common jamming forms are also studied. Pertinently put forward the corresponding interference suppression methods, In order to improve the anti-jamming ability of the satellite navigation system, the main research content of this paper is also focused on two aspects: the evaluation method of navigation signal reception performance under jamming environment and the research of interference suppression method. In this paper, the performance evaluation method of GNSS space signal in jamming environment is studied systematically, and the performance of frequency domain, acquisition, tracking, demodulation and so on are analyzed. This paper synthetically reflects the receiving performance of navigation receiver in jamming environment. Aiming at the evaluation of intersignal interference (ISI), which is widely concerned in the world at present, a new method which can directly evaluate the interference is proposed, which is different from the existing methods in the world. That is, using the interference factor k ~. As an evaluation parameter of inter-signal interference, the greater the jam is, the greater the interference is. This method can be used to evaluate the magnitude of inter-signal interference simply and accurately. At the same time, this paper also makes a detailed analysis and research on the receiving performance of Gao Si white noise environment and other jamming environment. A comprehensive assessment of the impact of various interference on GNSS signals. Secondly, different interference suppression methods are studied in this paper. For common narrowband interference forms, narrow band interference can be effectively removed by LMS linear prediction technology. So as to improve the anti-jamming ability of the received signal, but for wideband interference, the general time domain or frequency domain suppression method is not good for its interference suppression effect. Therefore, the suppression of wideband interference is one of the emphases of this paper. In this paper, the linear FM wideband interference and sinusoidal FM wideband interference are deeply studied, and two methods of interference suppression are given for each interference. Through the simulation results, the suitable conditions of each interference suppression method are given. Finally, in order to verify the correctness of the proposed GNSS signal reception performance evaluation method and interference suppression method, an experimental verification platform is designed. The actual GNSS satellite navigation signals are collected and different types of interference are superimposed. Then the interference suppression method proposed in this paper is used to suppress the interference. The change and improvement of the reception performance of GNSS signal before and after interference suppression are analyzed. Thus, the feasibility and effectiveness of the proposed interference suppression method are verified.
【学位授予单位】：中国科学院研究生院（国家授时中心）
【学位级别】：博士
【学位授予年份】：2014
【分类号】：P228.4

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