基于OFDM波形的机载MIMO雷达主瓣灵巧干扰抑制方法

When smart jamming entering into radar receiver from the main lobe of antenna, the jamming signal will construct dense false targets which are highly similar to the true target in spatial, temporal and frequency domains, and then the target signal detection and parameter estimation of radar are seriously affected. This fund utilize the frequency division advantage of OFDM(Orthogonal Frequency Division Multiplexing) technology to improve the system freedom to solve this pivotal problem. The equivalent between signal snap receive data of MIMO radar and multi-snap receive data of phase array radar is done to construct the "OFDM+MIMO" signal processing frame by combining the information from spatial, temporal and frequency domains. The model of smart jamming based on the time domain convolution modulation and multiplication modulation is constructed, and the blanket component and the deceptive component of smart jamming are factorized. According to the distance dependence of the components before and after data compensation, the subspace projection is utilized to suppress the deceptive component before data compensation, and the covariance matrix of clutter and the blanket component is estimated, then the targets detection is achieved in the transmitter- receiver-time domain. The production of the fund will provide a new technical approach to solve the main lobe smart jamming suppression problem of airborne MIMO radar, which is of great significance and broad application foreground in the military domain.

当灵巧干扰从天线主瓣进入时，雷达将接收到在空域、时域和频域都高度逼真的密集相干假目标信号，严重影响目标信号的检测及目标参数的估计。为解决这一关键难题，本项目从提高系统自由度这一根本途径入手，巧妙利用OFDM信号的频率分集优势，通过将MIMO雷达的单快拍接收数据等效为相控阵的多快拍接收数据，构建出“OFDM+MIMO”空时频三信息域联合的信号处理架构，建立基于卷积调制和乘积调制的统一灵巧干扰模型，分解出灵巧干扰的压制性分量和欺骗性分量，并根据其在数据补偿前后不同的距离依赖性，先利用子空间投影技术实现补偿前数据中欺骗性分量抑制，再利用补偿后数据估计杂波和压制性分量的协方差矩阵，在发射-接收-时间三维空间上进行目标检测。项目研究成果为解决机载雷达主瓣的灵巧干扰抑制难题提供了一条崭新的技术途径，将进一步推动机载MIMO雷达杂波和干扰同时抑制技术的发展，在军事领域具有十分广阔的应用前景。

本项目从提高系统自由度这一根本途径入手，将OFDM波形与MIMO 体制相结合，研究了机载MIMO雷达主瓣灵巧干扰抑制方法，提高了其在杂波和干扰背景下的目标检测性能。具体内容如下：（1）建立了机载OFDM-MIMO雷达目标回波模型和灵巧干扰统一模型，设计了其空时自适应处理的技术方案；（2）巧妙利用OFDM波形的频率分集优势，在发射-接收-距离参数空间内实现了目标和干扰的有效区分；（3）针对主瓣灵巧干扰的距离、速度和角度三维参数欺骗，将联合波门处理模型和贝叶斯估计思想结合，利用可逆跳跃马尔科夫链方法实现了波束内目标个数和位置参数的联合估计；（4）利用跳频PRI序号和MPPSK波形，提出了基于脉冲分集和波形水印的灵巧干扰对抗方法；（5）结合时频分析、压缩感知和盲原分离等理论，提出了基于参数估计、时域选通、信号重构的多种通道内灵巧干扰抑制方法。发表论文37篇，其中SCI 检索12篇，EI 检索7篇；出版专著2 部；申请国家发明专利7项，其中2项已授权；培养青年教师1名，博士后1名，博士生4名，硕士生5名。项目研究成果为解决机载雷达主瓣灵巧干扰抑制难题提供了一条新的技术途径，将进一步推动机载MIMO雷达杂波和干扰同时抑制技术的发展，在军事领域具有广阔的应用前景。