应用于卫星导航终端的自适应抗干扰天线空时算法研究
发布时间：2019-07-02 14:00
【摘要】：随着无线通信技术的迅猛发展,人类生活的空间范围内充斥着各种电磁信号,这些故意或无意的电磁信号已经极大影响有用信号的正常接收。空时自适应抗干扰(STAP)技术通过分析信号特征,利用阵列空域调零和时域滤波技术在空时两个维度抑制干扰信号并保障有用信号接收。特别是在卫星导航接收中,STAP技术可以极大提升接收机在复杂电磁环境下正常工作的能力。本文以北斗导航接收系统为应用背景,研究分析STAP算法基本原理结合天线阵列数值仿真对空域调零和时域滤波技术展开研究。基于空域自适应处理(SAP)理论建立了数学模型,分别推导了最大信干比准则、最小均方差准则、最大似然准则和最小方差准则条件下的最优权矢量表达式；分析了四种准则条件下天线阵列的空域响应特性。根据卫星导航信号特点,本文选择基于最小方差准则的功率倒置算法开展研究。建立了基于Matlab的仿真模型,分析了阵列参数对阵列空域响应变化的影响；对比了四阵元方阵、Y阵空域响应特性,验证了在紧凑结构中参考阵元动态选取条件下方阵综合性能优于Y阵；分析了天线阵列通道不一致性和阵元互耦对空域响应特性的影响：1)阵元幅相误差在单干扰条件下会导致空域响应特性变差。2)阵元互耦误差会导致系统空域响应特性严重恶化,特别在大干信比条件下。针对阵元互耦误差问题提出了互耦矩阵补偿、降耦等方法改善系统性能。建立了空时自适应(STAP)数学模型,推导了功率倒置算法下的最优权矢量表达式；仿真分析了高斯干扰条件下时域参数对空时响应特性的影响,为时域阶数和快拍数取值提供依据；仿真分析了周期脉冲干扰、调频干扰下时域参数变化规律。分析表明,不同干扰条件下时域参数的选取具有差异性。采用电磁仿真软件建立了四元圆极化微带天线方阵,仿真优化了天线参数,完成了设计、加工和测试工作。无源天线阵列测试数据与仿真结果相近,满足使用要求。有源系统级抗干扰测试数据与仿真结果存在一定差距,主要由天线阵元互耦、数据精度、算法结构等因素导致。
[Abstract]:With the rapid development of wireless communication technology, the space range of human life is full of all kinds of electromagnetic signals, these intentional or unintentional electromagnetic signals have greatly affected the normal reception of useful signals. Space-time adaptive anti-interference (STAP) technology uses array spatial zeroing and time-domain filtering techniques to suppress interference signals in space-time dimensions and ensure useful signal reception by analyzing signal characteristics. Especially in satellite navigation reception, STAP technology can greatly improve the ability of the receiver to work normally in complex electromagnetic environment. In this paper, based on the application background of Beidou navigation and receiving system, the basic principle of STAP algorithm and the numerical simulation of antenna array are studied to study the spatial zero adjustment and time domain filtering technology. Based on the (SAP) theory of spatial adaptive processing, the mathematical model is established, and the optimal weight vector expressions under the conditions of maximum signal-to-interference ratio criterion, minimum mean square error criterion, maximum likelihood criterion and minimum variance criterion are derived respectively, and the spatial response characteristics of antenna arrays under four criteria are analyzed. According to the characteristics of satellite navigation signal, the power inversion algorithm based on minimum variance criterion is selected in this paper. The simulation model based on Matlab is established, and the influence of array parameters on the spatial response of the array is analyzed, and the spatial response characteristics of four-element square array and Y-array are compared, and it is verified that the comprehensive performance of square array is better than that of Y matrix under the condition of dynamic selection of reference elements in compact structure. The influence of antenna array channel inconsistency and array element mutual coupling on spatial response characteristics is analyzed: 1) the amplitude and phase error of array elements will lead to the deterioration of spatial response characteristics under the condition of single interference. 2) the mutual coupling error of array elements will lead to the serious deterioration of the spatial response characteristics of the system, especially under the condition of large dry signal ratio. Aiming at the problem of mutual coupling error of array elements, mutual coupling matrix compensation and decoupling methods are proposed to improve the performance of the system. The mathematical model of space-time adaptive (STAP) is established, and the expression of optimal weight vector under power inversion algorithm is derived. the influence of time-domain parameters on space-time response characteristics under Gaussian interference is simulated and analyzed, which provides the basis for the value of time-domain order and fast beat number, and the variation law of time-domain parameters under periodic pulse interference and frequency modulation interference is simulated and analyzed. The analysis shows that the selection of time domain parameters is different under different interference conditions. The quaternion circularly polarized microstrip antenna array is established by using electromagnetic simulation software. The antenna parameters are simulated and optimized, and the design, machining and testing work are completed. The test data of passive antenna array are similar to the simulation results, which meets the requirements of use. There is a certain gap between the anti-interference test data at the active system level and the simulation results, which is mainly caused by the mutual coupling of antenna elements, data accuracy, algorithm structure and so on.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN967.1
本文编号：2508990
[Abstract]:With the rapid development of wireless communication technology, the space range of human life is full of all kinds of electromagnetic signals, these intentional or unintentional electromagnetic signals have greatly affected the normal reception of useful signals. Space-time adaptive anti-interference (STAP) technology uses array spatial zeroing and time-domain filtering techniques to suppress interference signals in space-time dimensions and ensure useful signal reception by analyzing signal characteristics. Especially in satellite navigation reception, STAP technology can greatly improve the ability of the receiver to work normally in complex electromagnetic environment. In this paper, based on the application background of Beidou navigation and receiving system, the basic principle of STAP algorithm and the numerical simulation of antenna array are studied to study the spatial zero adjustment and time domain filtering technology. Based on the (SAP) theory of spatial adaptive processing, the mathematical model is established, and the optimal weight vector expressions under the conditions of maximum signal-to-interference ratio criterion, minimum mean square error criterion, maximum likelihood criterion and minimum variance criterion are derived respectively, and the spatial response characteristics of antenna arrays under four criteria are analyzed. According to the characteristics of satellite navigation signal, the power inversion algorithm based on minimum variance criterion is selected in this paper. The simulation model based on Matlab is established, and the influence of array parameters on the spatial response of the array is analyzed, and the spatial response characteristics of four-element square array and Y-array are compared, and it is verified that the comprehensive performance of square array is better than that of Y matrix under the condition of dynamic selection of reference elements in compact structure. The influence of antenna array channel inconsistency and array element mutual coupling on spatial response characteristics is analyzed: 1) the amplitude and phase error of array elements will lead to the deterioration of spatial response characteristics under the condition of single interference. 2) the mutual coupling error of array elements will lead to the serious deterioration of the spatial response characteristics of the system, especially under the condition of large dry signal ratio. Aiming at the problem of mutual coupling error of array elements, mutual coupling matrix compensation and decoupling methods are proposed to improve the performance of the system. The mathematical model of space-time adaptive (STAP) is established, and the expression of optimal weight vector under power inversion algorithm is derived. the influence of time-domain parameters on space-time response characteristics under Gaussian interference is simulated and analyzed, which provides the basis for the value of time-domain order and fast beat number, and the variation law of time-domain parameters under periodic pulse interference and frequency modulation interference is simulated and analyzed. The analysis shows that the selection of time domain parameters is different under different interference conditions. The quaternion circularly polarized microstrip antenna array is established by using electromagnetic simulation software. The antenna parameters are simulated and optimized, and the design, machining and testing work are completed. The test data of passive antenna array are similar to the simulation results, which meets the requirements of use. There is a certain gap between the anti-interference test data at the active system level and the simulation results, which is mainly caused by the mutual coupling of antenna elements, data accuracy, algorithm structure and so on.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN967.1
【参考文献】
相关期刊论文 前2条
1 徐瑞;朱筱虹;赵金贤;;对导航标准体系建设的若干思考[J];测绘通报;2010年11期
2 刘拥军;胡捍英;;GPS频域抗干扰算法研究[J];信号处理;2009年11期
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