卫星干扰源定位与自适应波束形成技术研究

发布时间：2018-01-03 04:10

本文关键词：卫星干扰源定位与自适应波束形成技术研究　出处：《电子科技大学》2016年硕士论文　论文类型：学位论文

【摘要】：在卫星通信中,卫星平台容易受到各种有意或无意的射频干扰。近年来,基于自适应阵列天线的空域抗干扰技术被广泛地应用到卫星通信系统中,以此来解决卫星通信中的干扰问题。空域抗干扰技术的基本思想就是根据干扰和信号环境对各个天线阵元的加权系数值进行自适应调整,从而使天线方向图的零陷位置与干扰源方向对齐,同时保证在期望信号方向上的方向图增益最大。从空域滤波的角度,可以将干扰源定位技术和自适应波束形成技术有效地结合起来,从而实现高性能的空域滤波。因此,如何快速精确地估计出干扰源的来波方向信息和如何利用干扰源的来波方向进行自适应调零,是实现高性能空域滤波的两个关键问题。在此背景下,本文从干扰源定位和干扰抑制两个方面展开研究。在卫星干扰源定位方面,空间谱估计技术为干扰源的高精度和高分辨定位奠定了坚实的理论基础,在卫星天线阵列接收信号的基础上运用空间谱估计技术可实现单颗卫星对干扰源来波方向的精确估计。在干扰源的抑制方面,结合干扰源来波方向的先验信息,运用自适应波束形成技术可以实现在空域上对干扰源进行抑制或消除。本文在均匀直线阵列所接收到的少量快拍数据的基础上对窄带信号的波达方向估计算法进行研究,提出了一种基于扩展伪协方差矩阵的DOA估计方法,一种基于矢量重构的DOA估计方法以及一种基于奇异值分解和相干积累的DOA估计方法,扩展了一类基于数据预处理的单快拍DOA估计方法,并仿真分析了几种算法在相干干扰条件下的DOA估计性能。在均匀圆形阵列所接收的宽带相干信号模型的基础上,针对一类基于角频分离的宽带相干信号的DOA估计算法进行改进,并针对阵列构型对算法的性能进行简要分析。在获得干扰源DOA信息的前提下,对基于信号DOA估计信息的自适应波束形成算法进行研究,提出了一种基于不确定集和投影子空间的波束形成算法,以及一种改进的多波束最小方差波束形成算法,且这两种算法在阵列输出SINR方面和稳健性方面均具有较好的性能。
[Abstract]:In satellite communications, satellite platforms are vulnerable to various intentional or unintentional radio frequency interference. In recent years, spatial anti-jamming technology based on adaptive array antenna has been widely used in satellite communication systems. In order to solve the interference problem in satellite communication, the basic idea of spatial anti-jamming technology is to adaptively adjust the weighting coefficients of each antenna array element according to the interference and signal environment. In order to align the zero trapping position of the antenna pattern with the direction of the interference source and ensure the maximum gain of the pattern in the desired signal direction. The interference source location technology and adaptive beamforming technology can be effectively combined to achieve high performance spatial filtering. How to estimate the direction information of the interference source quickly and accurately and how to adjust the zero adaptively using the direction of the interference source are two key problems to realize the high performance spatial filtering. In this paper, the interference source location and interference suppression are studied. In satellite interference source location, the spatial spectrum estimation technology has laid a solid theoretical foundation for high precision and high resolution location of interference source. On the basis of receiving signals from satellite antenna array, the spatial spectrum estimation technique can be used to accurately estimate the direction of the interference source by a single satellite. In the aspect of interference source suppression, the prior information of the direction of the interference source can be combined. Adaptive beamforming technique can be used to suppress or eliminate interference sources in airspace. Based on a small amount of rapid-shot data received by a uniform linear array, the DOA estimation algorithm for narrowband signals is proposed in this paper. Research. A DOA estimation method based on extended pseudo covariance matrix, a DOA estimation method based on vector reconstruction and a DOA estimation method based on singular value decomposition and coherent integration are proposed. A class of DOA estimation methods based on data preprocessing are extended. The DOA estimation performance of several algorithms under coherent interference is analyzed by simulation, and based on the wideband coherent signal model received by uniform circular array. The DOA estimation algorithm for wideband coherent signals based on angle frequency separation is improved, and the performance of the algorithm is analyzed briefly according to array configuration. The DOA information of interference source is obtained. The adaptive beamforming algorithm based on signal DOA estimation information is studied, and a beamforming algorithm based on uncertain set and projection subspace is proposed. And an improved multibeam minimum variance beamforming algorithm is proposed. Both algorithms have good performance in the aspect of array output SINR and robustness.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN927.2

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