基于合成阵列的GNSS抗欺骗式干扰算法研究

发布时间：2018-05-26 20:14

本文选题：全球导航卫星系统 + 欺骗式干扰　；参考：《中国民航大学》2017年硕士论文

【摘要】：全球卫星导航系统(Global Navigation Satellite System,GNSS)具有高精度导航定位的优势,在当今社会各个领域得到了越来越广泛的应用。然而,由于GNSS信号到达用户接收机时极其微弱,容易受到各类干扰的影响。其中,欺骗式干扰的功率远低于接收机噪声水平且与真实卫星信号在时频域都具有相同的格式,具有很强的隐蔽性,给卫星导航带来的危害性极大。因此,需要针对欺骗式干扰的特点利用新的方法对它进行有效的抑制。在现有的欺骗式干扰抑制方法中,多天线技术可以利用接收信号的空间到达角信息把真实卫星信号和欺骗式干扰分开。然而,它的性能受阵元通道误差和阵列孔径的影响。因此,本文借鉴合成孔径雷达的思想,考虑利用单个天线运动形成的合成阵列代替传统天线阵进行欺骗式干扰的抑制。本论文从如下几个方面对合成阵列抑制欺骗式干扰的方法进行了研究:第一,分析了欺骗式干扰和合成阵列的产生机理,推导给出了合成阵列接收信号模型;第二,提出了数据域合成阵列欺骗式干扰抑制方案:在数据域合成阵列数据模型下,首先分别利用MUSIC算法和RELAX算法对多个欺骗式干扰源的来向进行估计,再设计自适应权向量零陷干扰。在不考虑合成阵列位置误差影响下,该算法与理想传统阵列性能一致,较有通道误差的传统阵列性能更好,验证了合成阵列的优势;第三,针对合成阵列虚拟阵元之间时间间隔不满足整数倍扩频码周期的情况,提出了利用参考天线的合成阵列欺骗式干扰抑制方案:首先将运动天线和静态参考天线接收到数据做共轭点乘,得到新的观测数据,再利用实数RELAX算法进行欺骗式干扰源来向估计与抑制。该算法不受虚拟阵元间隔时间限制,且具有更好的来向估计与干扰抑制能力;第四,针对形成合成阵列的轨道并非完全精确可控,即存在阵元位置误差的情况,提出了轨迹误差稳健的合成阵列欺骗式干扰抑制方案:利用解重扩算法估计出每个伪随机噪声(Pseudo Random Noise,PRN)码对应的解重扩权矢量,利用欺骗式干扰PRN来自同一个方向的特点,通过计算两两权矢量之间的相关性把欺骗式干扰从真实卫星信号中分离出来,并利用欺骗PRN的权矢量构造正交投影矩阵,从而抑制掉欺骗式干扰。该算法不需要估计欺骗式干扰来向,对合成阵列阵元位置误差不敏感。
[Abstract]:Global Navigation Satellite system (GNSS) has the advantage of high precision navigation and positioning, and has been more and more widely used in various fields of society today. However, the GNSS signal is very weak when it arrives at the user receiver, so it is vulnerable to various kinds of interference. Among them, the power of deceptive jamming is far lower than the receiver noise level and has the same format as the real satellite signal in time-frequency domain, and has strong concealment, which brings great harm to satellite navigation. Therefore, a new method should be used to suppress deception interference effectively. Among the existing deceptive jamming suppression methods, multi-antenna technology can separate the real satellite signal from the deception interference by using the spatial angle of arrival information of the received signal. However, its performance is affected by the channel error and the aperture of the array. Therefore, using the idea of synthetic Aperture Radar (SAR) for reference, we consider using the synthetic array formed by the motion of a single antenna instead of the traditional antenna array to suppress the deceptive interference. In this paper, the methods to suppress deceptive interference by synthetic array are studied from the following aspects: firstly, the mechanism of deception interference and synthetic array is analyzed, and the receiving signal model of synthetic array is derived. A deceptive interference suppression scheme based on data domain synthesis array is proposed. In the data domain synthesis array data model, the MUSIC algorithm and the RELAX algorithm are used to estimate the direction of multiple spoofed interference sources, respectively. Redesigning adaptive weight vector zero trapping interference. Without considering the position error of synthetic array, the performance of this algorithm is consistent with that of ideal traditional array, which is better than that of traditional array with channel error, which verifies the advantages of synthetic array. When the time interval between virtual array elements of synthetic array does not satisfy the period of spread spectrum code, A deceptive interference suppression scheme using a synthetic array of reference antennas is proposed. Firstly, the conjugate point multiplication of the received data from the moving antenna and the static reference antenna is performed to obtain the new observation data. Then the real RELAX algorithm is used for deceptive interference source estimation and suppression. The algorithm is not limited by the interval time of the virtual array elements, and has better ability of direction estimation and interference suppression. Fourthly, the orbit of the composite array is not completely accurate and controllable, that is, the position error of the array element exists. In this paper, a robust path error suppression scheme for synthetic array deceptive interference is proposed. The despreading weight vector corresponding to every pseudo Random Random PRN code is estimated by despreading algorithm, and the deceptive interference PRN comes from the same direction. The deceptive interference is separated from the real satellite signal by calculating the correlation between the two weight vectors, and the orthogonal projection matrix is constructed by using the weight vector of the deceptive PRN to suppress the deceptive interference. The algorithm does not need to estimate the deceptive interference and is insensitive to the position error of composite array elements.
【学位授予单位】：中国民航大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN967.1

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