MIMO雷达抗干扰性能研究

发布时间：2018-05-21 17:41

本文选题：MIMO雷达 + 雷达干扰　；参考：《电子科技大学》2017年硕士论文

【摘要】：作为一种新兴体制的雷达,多输入多输出(multiple-input multiple-output,MIMO)雷达成为雷达研究领域的热点之一。目前关于MIMO雷达的信号处理研究主要集中在目标检测、参数估计、波形设计等方面。由于MIMO雷达出现时间较晚,关于其在对抗环境下的电子反对抗(electronic counter-countermeasures,ECCM)性能的研究目前并不多见。基于此,本文主要研究了集中式MIMO雷达的ECCM性能,包括抗侦察与抗干扰两方面,其中对于MIMO雷达抗干扰的研究集中在空域上,所做的工作主要包括以下几个方面。首先,介绍了 MIMO雷达的信号处理结构,包括发射信号模型和接收信号处理流程。在此基础上,介绍了常见的雷达干扰及对抗方法。其次,研究了雷达信号截获的原理,针对影响截获性能的主要因素,即发射信号的空间功率分布水平,分析了 MIMO雷达的抗截获性能。研究了雷达信号脉内调制类型识别的原理,并针对信号识别过程中特征提取这一关键步骤,研究了MIMO雷达信号的时频特征,进而对其抗识别性能进行分析。之后,采用空域滤波,即自适应波束形成的方法进行MIMO雷达抗干扰性能研究。从MIMO雷达接收端信号处理流程入手,分析了其联合方向图的特点,包括主瓣宽度、旁瓣高度和自由度优势。对于自适应波束形成中的两个非理想因素,研究了稳健波束形成的相关算法,将它们移植到MIMO雷达上。结合MIMO雷达联合导向矢量的结构特点,给出了一种降低时间复杂度的稳健算法,并进行了仿真验证。最后,采用频率分集阵列(frequency diverse array, FDA)技术进行主瓣干扰抑制研究。普通的波束形成算法在干扰位于主瓣方向时会影响目标信号的接收,造成干扰抑制性能下降。采用了 FDA结构的FDA-MIMO雷达的联合方向图具有角度-距离二位分辨能力,可以在主瓣方向通过距离维进行干扰抑制。此外,针对线性频率偏移量的FDA方向图存在距离周期性这一缺陷,本文采用了对数形式的频率偏移量进行改进,仿真结果验证了所提方法的有效性。
[Abstract]:As a new radar system, multiple-input multiple-output MIMO radar has become one of the hotspots in radar research field. At present, the research of MIMO radar signal processing is mainly focused on target detection, parameter estimation, waveform design and so on. Due to the late appearance of MIMO radar, there are few researches on its electronic countermeasures-counter ECCM performance in antagonistic environment. Based on this, this paper mainly studies the ECCM performance of centralized MIMO radar, including anti-reconnaissance and anti-jamming, in which the research of anti-jamming of MIMO radar is focused on the airspace, the work done mainly includes the following aspects. Firstly, the signal processing structure of MIMO radar is introduced, including the transmitting signal model and the receiving signal processing flow. On this basis, the common radar jamming and countermeasures are introduced. Secondly, the principle of radar signal interception is studied, and the anti-interception performance of MIMO radar is analyzed according to the main factors that affect the interception performance, namely, the spatial power distribution level of the transmitted signal. The principle of intrapulse modulation type recognition of radar signal is studied. Aiming at the key step of feature extraction in the process of signal recognition, the time-frequency feature of MIMO radar signal is studied and its anti-recognition performance is analyzed. After that, the anti-jamming performance of MIMO radar is studied by using spatial filtering, that is, adaptive beamforming. Based on the signal processing flow of the MIMO radar receiver, the characteristics of the joint pattern are analyzed, including the width of the main lobe, the height of the sidelobe and the advantages of the degree of freedom. For two non-ideal factors in adaptive beamforming, the correlation algorithms of robust beamforming are studied, and they are transplanted to MIMO radar. A robust algorithm to reduce the time complexity is presented based on the structural characteristics of the joint guidance vector of MIMO radar, and the simulation results are given. Finally, the frequency diversity array frequency diverse array, FDA) technique is used to study the main lobe interference suppression. The conventional beamforming algorithm will affect the receiver of the target signal when the interference is in the direction of the main lobe, resulting in the degradation of interference suppression performance. The joint pattern of FDA-MIMO radar with FDA structure has the ability of angle-range binary resolution, which can suppress the interference in the direction of the main lobe through the range dimension. In addition, the FDA pattern of linear frequency offset has the defect of distance periodicity. In this paper, the logarithmic frequency offset is improved. The simulation results verify the effectiveness of the proposed method.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN958

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