一种分数阶域的密集假目标干扰抑制算法  

An Algorithm for Suppressing Jamming of Dense False Targets in Fractional Fourier Transform Domain

作　　者：张亮 王国宏 张顺义 张翔宇 孙殿星 李思文 ZHANG Liang;WANG Guohong;ZHANG Shunyi;ZHANG Xiangyu;SUN Dianxing;LI Siwen(Institute of Information Fusion,Naval Aviation University,Yantai,Shandong 264001,China;The 94326 Unit,Jinan 250000,China;China Electronics Technology Instruments Co.Ltd.,Qingdao,Shandong 266555,China)

机构地区：[1]海军航空大学信息融合研究所,山东烟台264001 [2]中国人民解放军94326部队,济南250000 [3]中电科仪器仪表有限公司,山东青岛266555

出　　处：《西安交通大学学报》2020年第12期79-87,共9页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(61731023,61701519);山东省“泰山学者”攀登计划专项资金资助项目。

摘　　要：针对线性调频(LFM)相参雷达抗自卫式密集假目标干扰问题,提出一种分数阶域的密集假目标干扰抑制算法。雷达遭受干扰后,首先发射调频斜率捷变LFM(SV-LFM)波形,得到1个相干处理间隔回波;其次,最大高阶矩准则估计各脉冲重复周期干扰调频斜率,确定分数阶傅里叶变换(FRFT)最优阶次;然后,计算回波最优阶次FRFT,通过峰值遮盖滤除部分干扰;最后,对滤除干扰后的回波进行脉冲压缩、相参积累,最终实现干扰抑制。对于发射SV-LFM波形的雷达,其脉冲压缩、相参积累本身对密集假目标干扰具有一定抑制作用,结合干扰滤除处理,能够取得更佳抑制效果。实验结果表明,所设计的变带宽SV-LFM波形与雷达动目标检测具备较高兼容性,相比理想不捷变,真实目标有效检测临界信噪比小于1 dB;所提算法对干扰抑制后的真实目标有效检测临界干信比提高约20 dB,假目标数量减少约40%。An algorithm for suppressing jamming in the fractional Fourier transform(FRFT)domain is proposed to solve the problem of self-screening dense false target jamming in linear frequency modulation(LFM)coherent radar.Firstly,when LFM radar is jammed,slope varying LFM(SV-LFM)waveform is transmitted to obtain a coherent processing interval echo.Then,the maximum high-order moment criterion is used to estimate the jamming slope in each pulse repetition period and determine the optimal order of FRFT.The optimal order FRFT of the echo is calculated,and the FRFT peak value covers and filters out part of the jamming.Finally,pulse compression and coherent integration are carried out for the filtered echo to realize the final suppression of jamming.For the radar of SV-LFM waveform,the processing of pulse compression and coherent integration have certain suppression effects on dense false targets,and better suppression effect can be achieved by combining with jamming filtering.Experimental results show that SV-LFM with variable bandwidth has higher compatibility with radar moving target detection,and the critical signal to noise ratio of real target detection is less than 1 dB,compared to ideal non-agility case.After jamming suppression,the critical jamming to signal ratio increases by about 20 dB,and the number of false targets reduces by about 40%.

关 键 词：密集假目标干扰 雷达 线性调频 调频斜率捷变 分数阶傅里叶变换 干扰抑制 

分 类 号：TN958[电子电信—信号与信息处理]