基于RFT的随机调频周期LFMCW雷达微弱目标检测  

Weak Target Detection of Random Frequency Modulation Period LFMCW Radar Based on RFT

作　　者：祁萍萍 李琦 韩壮志 QI Pingping;LI Qi;HAN Zhuangzhi(School of Electronic and Information Engineering,Hebei University of Technology,Tianjin 300401,China;Department of Electronic and Optical Engineering,Shijiazhuang Campus of Army Engineering University,Shijiazhuang 050003,China)

机构地区：[1]河北工业大学电子信息工程学院,天津300401 [2]陆军工程大学石家庄校区电子与光学工程系,河北石家庄050003

出　　处：《无线电工程》2022年第6期996-1003,共8页Radio Engineering

基　　金：国家自然科学基金(61601496);河北省自然科学基金(F2019506037)。

摘　　要：针对线性调频连续波(Linear Frequency Modulated Continuous Wave,LFMCW)雷达对微弱目标进行检测时回波信噪比较低和多普勒模糊问题,采用随机调频周期Radon-Fourier变换(RFT)对目标的能量进行积累并解决盲速旁瓣问题。通过RFT对LFMCW雷达的回波差拍信号在速度维和距离维进行联合搜索,估计目标的速度和距离信息,针对固定调频周期下利用RFT会产生盲速旁瓣的问题,在固定调频周期的基础上增加随机抖动量来抑制盲速旁瓣,通过分析添加随机抖动量的大小与盲速旁瓣抑制效果的关系,表明添加特定的随机抖动量可以有效地抑制盲速旁瓣。理论和实验结果表明,该算法可以在信噪比较低的情况下准确地检测出微弱目标,提升了信噪比且有效解决了盲速旁瓣问题。To solve the problems of low echo signal-to-noise ratio and Doppler ambiguity when Linear Frequency Modulated Continuous Wave(LFMCW)radar detects weak targets,random frequency modulation period Radon Fourier Transform(RFT)is used to accumulate the energy of targets and solve the problem of blind speed side lobe.Through RFT,the echo beat signal of LFMCW radar is jointly searched in velocity and range dimensions to estimate the velocity and range information of the target.To solve the problem that RFT will produce blind speed side lobe under fixed frequency modulation period,the amount of random jitter is added on the basis of fixed frequency modulation period to suppress the blind speed side lobe.By analyzing the relationship between the magnitude of random jitter and the effect of blind speed side lobe suppression,it shows that adding a specific amount of random jitter can effectively suppress blind speed side lobe.Theoretical and experimental results show that the algorithm can accurately detect weak targets under the condition of low signal-to-noise ratio,improve the signal-to-noise ratio,and effectively solve the problem of blind speed side lobe.

关 键 词：微弱目标检测 Radon-Fourier变换 盲速旁瓣 随机调频周期 

分 类 号：TN957.51[电子电信—信号与信息处理]