雷达抗干扰技术研究

【作者】 高娜；

【导师】 盛卫星；

【作者基本信息】 南京理工大学 ， 通信与信息系统， 2008， 硕士

【摘要】 自雷达问世以来,雷达干扰与抗干扰措施之间一直进行着激烈的竞争,雷达对抗在现代战争中居于日益重要的地位。本文主要研究雷达有源压制性干扰的抗干扰算法,主要包括下面几个方面的内容:(1)、在介绍了有源压制性干扰原理的基础上,分析了噪声调幅干扰和噪声调频干扰的特性、建立了数学模型、研究了它们对雷达接收机的影响。(2)、从时域和频域上分别对有源压制性干扰进行特性分析,提取了多个受噪声影响相对较小的特征参数,并且定量地分析了在不同干噪比下干扰信号的分布情况,从不同角度采用不同方法研究了雷达有源压制性干扰信号的特征。(3)、针对干扰信号的特征,采用相应的抗干扰算法进行干扰抑制,对于噪声调幅干扰,通过估计干扰信号载频和初始相位,再对信号进行解调,利用频域对消方法抑制干扰信号分量。对于噪声调频干扰,利用Morlet小波变换在时间、频域局部化信号的能力,对雷达信号进行小波变换和相关处理,可极大限度的抑制噪声调频干扰和系统噪声。在此基础上,应用了一种通过包络滤波的宽带干扰抑制方法,仿真结果证明上述方法可以有效抑制干扰,尤其是对强干扰,相关输出使输出效果明显,并对以上几种抗干扰算法进行了性能评估。最终研究成果表明,本文所应用的算法取得了较好的抗干扰效果,符合干扰抑制的要求。更多还原

【Abstract】 Since the development of radar, radar jamming and anti-jamming measures have been fiercely competed. They become a much more important position in modern warfares. This thesis is focused on the study of anti-jamming algorithms. The main works are as follows: (1). Based on the theory of active suppression jamming, The character of noise amplitude modulation (NAM) and noise frequency modulation (NFM) are analyzed, The mathematic models are established and the impacts on radar receivers are researched. (2). Active suppression jamming is analyzed from the time and frequency domain. The characters almost without the influence of the noise are extracted. At the same time, the features quantificationally by modern signal processing are studied when Jamming-to-Noise Rate (JNR) varies in a certain range. Different feature extraction methods in different domains are used to explore the characteristics of active suppression jamming. (3) For NAM, the carrier frequency and initial phase of the jamming siginal are estimated, and then, the echo signal is demodulated with the estimated jamming carrier frequency, the jamming may be suppressed with frequency domain cancellation. For NFM, morlet wave transform and correlation processing are used which can effectively restrain the disturbance of NFM and system noise. Based on this, a simple technique of excising interference through envelope filtering is put forward. It is found by simulation that the technique applied in this paper can effectively excise the broadband interference, especially for strong interference. And the correlation output is improved obviously. At the same time, the performance of the above anti-jamming algorithm is estimatedThe results show the applied algorithm is effective for jamming resistance.更多还原