北斗四阵元天线自适应抗干扰技术的研究

发布时间：2019-01-18 18:12

【摘要】：全球卫星导航系统具有授时精准、定位精度高、实时性较强等特点,因而其在科研、农业、军事等多领域得到广泛应用。然而由于卫星与地球表面相距较远,信号发射功率较弱,同时人为有意或无意干扰的日益增多,导致用户段接收的导航信号质量较差,无法精准定位。针对该情况,构建一个完备的卫星信号用户段抗干扰方案,找到一种高效、低成本、稳定性强的实现方法,设计出一种即便在电磁干扰环境相对恶劣情况下,依然能够抑制干扰,捕获导航信号,正常精确定位的抗干扰产品是非常重要的。本课题依托某公司项目,以北斗卫星导航接收设备硬件为开发平台,自适应抗干扰技术为研究对象,着重分析并研究了阵列天线、干扰抑制算法、通道失配校正等技术。首先,本文阐述了抗干扰技术研究现状,同时分析研究了抗干扰技术的发展趋势。紧接着分析了我国北斗导航系统的发展历程,系统组成及工作原理,其干扰类型、干扰实施方式及抗干扰措施。接着分析了自适应滤波器的类型及基本结构组成,较为全面地推导并对比了各种自适应算法收敛准则,并且对自适应天线原理、天线阵列模型及天线阵列结构对抗干扰性能影响进行了比较分析。然后,根据北斗导航电文的信号特征,及相关项目成员给的经验指导,确定利用基于多线性约束最小方差准则的功率倒置算法进行干扰信号的抑制。然而,在对功率倒置(PI)算法原理分析、算法公式迭代推导时,发现传统的PI算法对强干扰信号抑制效果明显,而对弱干扰信号抑制效果不佳。针对该种情况,在本文中提出了矩阵分解提取干扰子矩阵和噪声子矩阵方法,对该矩阵进行判断处理,进而使得在弱干扰情况下采用PI算法也能对该信号进行消弱滤除。同时设计该PI算法的框架,确定算法实现流程,然后对该算法在空域中基于不同阵列模型的抗干扰性能进行了 Matlab仿真,确定了抗干扰天线阵面结构为均匀方阵,并对阵型结构进行了优化。最后,先是对北斗四阵列天线硬件平台结构各模块的功能进行了详细说明,然后对抗干扰算法的设计实现进行说明。搭建测试环境,设置干扰源,采集北斗导航卫星信号作为输入信号,然后经过自适应算法的各模块,分析干扰抑制效果。采用Matlab结合ISE的方式,对设计的正确性进行了验证。
[Abstract]:Global satellite navigation system is widely used in many fields, such as scientific research, agriculture, military and so on. However, because the satellite is far away from the earth's surface, the signal transmitting power is weak, and the artificial or unintentional interference is increasing day by day, which leads to the poor quality of the navigation signal received by the user segment, which makes it impossible to locate accurately. In view of this situation, a complete anti-jamming scheme of satellite signal user segment is constructed, and an efficient, low-cost and stable implementation method is found, and a kind of EMI environment is designed even if the EMI environment is relatively bad. Still be able to suppress interference, capture navigation signals, normal accurate positioning of anti-jamming products is very important. Based on the project of a company, taking the hardware of Beidou satellite navigation and receiving equipment as the development platform and the adaptive anti-jamming technology as the research object, the paper emphatically analyzes and studies the array antenna, the interference suppression algorithm, the channel mismatch correction and so on. Firstly, this paper describes the current situation of anti-jamming technology, and analyzes the development trend of anti-jamming technology. Then it analyzes the development course, system composition and working principle, interference type, interference implementation mode and anti-interference measures of Beidou navigation system in China. Then, the types and basic structure of adaptive filter are analyzed, the convergence criteria of various adaptive algorithms are derived and compared, and the principle of adaptive antenna is analyzed. The effects of antenna array model and antenna array structure on anti-jamming performance are compared and analyzed. Then, according to the signal characteristics of Beidou navigation message and the experience guidance given by the relative item members, it is determined that the power inversion algorithm based on the multilinear constraint minimum variance criterion is used to suppress the interference signal. However, in the analysis of the principle of the power inversion (PI) algorithm and the iterative derivation of the algorithm formula, it is found that the traditional PI algorithm can suppress the strong interference signal obviously, but the weak interference signal suppression effect is not good. In this paper, a matrix factorization method is proposed to extract the interference submatrix and noise submatrix, and the matrix is judged and processed, so that the signal can be removed by using the PI algorithm in the case of weak interference. At the same time, the frame of the PI algorithm is designed, and the realization flow of the algorithm is determined. Then, the anti-jamming performance of the algorithm based on different array models in the airspace is simulated by Matlab, and the structure of the anti-jamming antenna array is determined to be a uniform square array. The formation structure is optimized. Finally, the function of each module of the hardware platform of Beidou four array antenna is explained in detail, and the design and implementation of anti-jamming algorithm are described. Set up the test environment, set up the interference source, collect the Beidou navigation satellite signal as the input signal, then analyze the interference suppression effect through each module of the adaptive algorithm. The correctness of the design is verified by Matlab and ISE.
【学位授予单位】：重庆三峡学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN967.1

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