LFM脉冲雷达转发式干扰对抗算法研究与实现

发布时间：2018-02-05 17:59

本文关键词： LFM脉冲数字射频存储器抗转发式欺骗干扰 stretch 相位量化脉间调相　出处：《南京理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：采用数字射频存储器(DRFM)技术的转发式干扰能够获得高相干信号处理增益,成为线性调频脉冲(LFM)雷达干扰对抗模块中亟待解决的难题,本文以LFM雷达对抗转发式干扰为应用背景,开展转发式干扰对抗方法研究与实现。本文主要工作如下:1.构建了 LFM脉冲雷达的接收信号和转发式距离欺骗干扰的模型,设计了一种基于相参处理间隔(CPI)回波stretch处理的抗距离欺骗干扰方法,通过时频解耦合实现目标与干扰分离,结合滤波处理达到干扰抑制效果。通过仿真验证了算法的正确性,分析了算法对信干比的改善性能,完成了算法在FPGA+DSP硬件平台上的移植与功能验证。2.利用DRFM干扰机的相位量化特性,设计了基于信号分离与平均相位统计次数方差抗转发式干扰的算法。该算法利用动目标检测的结果分离目标回波与干扰信号,然后运用分数阶傅里叶变换降噪,最后利用统计量平均相位统计次数方差实现目标与干扰的鉴别,通过仿真验证了算法在多假目标场景和低输入信噪比条件下的有效性。3.利用DRFM转发式干扰脉冲时间滞后特性,设计了基于多通道处理和脉间初相三次调制发射波形的抗转发式干扰方法。该方法通过多通道处理获取转发式干扰脉冲滞后的脉冲重复间隔(PRI)数,以此调整LFM脉冲初相三次调制系数,通过对回波进行分数阶傅里叶变换与遮蔽处理实现对干扰的抑制。通过仿真验证了算法在多目标场景下对抗转发式干扰的有效性。
[Abstract]:The high coherent signal processing gain can be obtained by the repeater jamming using digital RF memory (DRFM) technology, which is a difficult problem to be solved in the jamming countermeasure module of LFM LFM radar. In this paper, the application background of LFM radar against forward jamming is discussed. The main work of this paper is as follows: 1. The model of received signal and forward range deception jamming of LFM pulse radar is constructed. A range deception jamming method based on coherent processing interval (stretch) echo processing is designed. The separation of target and interference is realized by time-frequency decoupling. Through simulation, the correctness of the algorithm is verified, and the improved performance of the algorithm to the signal-to-interference ratio is analyzed. The transplant and function verification of the algorithm on FPGA DSP hardware platform is completed. 2. The phase quantization characteristic of DRFM jammer is used. An algorithm based on signal separation and average phase statistics is designed, which uses the result of moving target detection to separate target echo and jamming signal, and then uses fractional Fourier transform to reduce noise. Finally, the average phase statistics variance is used to identify the target and interference. The simulation results show that the algorithm is effective in multi-false target scene and low input SNR. 3. Using DRFM forward jamming pulse time delay characteristic. An anti-forward interference method based on multi-channel processing and three-pulse modulation is designed, which can obtain the number of pulse repetition interval (PRI) of forward jamming pulse lag. The third modulation coefficient of the initial phase of the LFM pulse is adjusted accordingly. The suppression of the interference is realized by fractional Fourier transform and shadowing of the echo, and the effectiveness of the algorithm in the multi-target scene is verified by simulation.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN974

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