OFDM外辐射源雷达线性调频干扰抑制  

Linear Frequency Modulation Interference Suppression for OFDM-Based Passive Radar

作　　者：饶云华[1] 丁添 谢德强[1] 万显荣[1] 易建新[1] RAO Yunhua;DING Tian;XIE Deqiang;WAN Xianrong;YI Jianxin(School of Electronic Information,Wuhan University,Wuhan,Hubei 430072,China)

机构地区：[1]武汉大学电子信息学院,湖北武汉430072

出　　处：《信号处理》2023年第2期202-211,共10页Journal of Signal Processing

基　　金：国家自然科学基金(61271400,U1933135,62071335,61931015);湖北省自然科学基金创新群体项目(2021CFA002)。

摘　　要：随着外辐射源雷达技术的快速发展和逐步应用,干扰问题日渐受到关注。本文以对OFDM外辐射源雷达工作性能带来极大影响的线性调频(Linear Frequency Modulation,LFM)干扰为研究对象,根据线性调频干扰信号模型,从理论上分析了多周期线性调频干扰对OFDM外辐射源雷达的干扰形态和特性,并推导了干扰带宽与相关时延宽度的关系,进而提出了一种自适应多周期线性调频干扰抑制方法。所提干扰抑制方法首先在频域进行干扰检测并估计线性调频干扰带宽,然后根据干扰带宽在距离多普勒谱上选取慢时间维序列构造干扰子空间,最后通过干扰子空间正交投影实现对多周期线性调频干扰的抑制。在不同干扰强度、干扰带宽以及线性调频周期条件下,以基底改善因子作为评估指标,仿真验证了所提方法的有效性和鲁棒性。With the rapid development and progressive application of passive radar technology,interference problems are a growing concern.This paper took linear Frequency Modulation(LFM)interference,which greatly affected the performance of OFDM-based passive radar,as the research object,and theoretically analyzed the interference pattern and characteristics of Multi-cycle LFM interference to OFDM-based passive radar according to the LFM interference signal model,and deduced the relationship between the interference bandwidth and the associated time delay width,and then proposed an adaptive Multi-cycle LFM interference suppression method.The proposed interference suppression method first detected the interference in the frequency domain and estimated the LFM interference bandwidth,then constructed an interference subspace on the Range Doppler spectrum by selecting a slow time dimensional sequence according to the interference bandwidth,and finally achieved the suppression of Multi-cycle LFM interference by orthogonal projection of the interference subspace.The effectiveness and robustness of the proposed method for interference suppression are verified by simulation under different conditions of interference intensity,interference bandwidth and LFM period,using the baseimprovement factor as the evaluation index.

关 键 词：OFDM外辐射源雷达 线性调频干扰 自适应抑制 子空间正交投影 

分 类 号：TN958.97[电子电信—信号与信息处理]