被动雷达阵列稀疏优化与FRI无网格DOA估计方法研究

目前，被动雷达、电子侦察及认知雷达等电子战系统面临在相控阵体制下的新应用，但受通道及结构限制，存在从多阵元中选取部分阵元实现优化设计和面对不同频率的敏捷布阵新问题。因此项目以受限非半波长、非均匀的稀疏优化阵列高精度DOA估计为目标，主要研究约束条件下的稀疏阵列优化与无网格DOA估计两个内容。创新性地提出基于强化学习的多目标稀疏阵列优化方法，以互质等稀疏阵列作为候选阵列和回放记忆单元，依据测角精度CRB、角分辨力、自由度等构成多目标优化函数，实现认知优化布阵。将有限新息率FRI理论扩展到稀疏阵列测向,提出基于FRI的稀疏阵列无网格DOA估计（FRIDA）方法，利用迭代过程求满足卷积约束的优化解，从而不依赖SDP过程。研究虚拟阵列扩展、插值滤波、信源数估计、二维FRIDA等问题。成果将为电子侦察等系统提供全新解决方案；促进DOA估计、FRI理论的应用与发展；也必将促进国家安全和国防事业的发展。

Currently, electronic warfare systems, such as passive radar, electronic reconnaissance and cognitive radar system, are facing a novel application with the develpment of phased array system. Due to the limitation of channels and structure, it is a new difficulty to how to select a few antennas from a multi-element phased array to realize optimal design and rapid array deployment for reconnaissance and direction finding. So under these constraints realizing non-half wavelength and non-uniform array design and high presion DOA estimation are main targets and research contents in this project.An innovative idea based on reinforcement learning is proposed to solve the multi-objective optimization function problem.The existence sparse array,such as co-prime array, is selected as candidate arrays and experience replay data. According to the optimization criterion where the DOA estimation presion(CRB),angle resolution,degree of freedom are considered, cognitive and optimal array design will be implemented. Meanwhile, Finite Rate of Innovation (FRI) sampling theory is applied to sparse array DOA estimation.So sparse arrays gridless DOA eatimation based on FRI(FRIDA) is investigated.Using this alogrithm, the iterative process instead of SDP process is used to solve the optimal solution satisfying the convolution constraints.Furthermore, for the sparse array DOA alogrithm,such as virtual array expansion,interpolation,filter, virtual array source number estimation, 2D-FRIDA will be studied. The project achievements will provide a new solution for the passive radar electronic reconnaissance system. This project can significantly promote the application and development of sparse array DOA estimation and FRI theory in electronic reconnaissance field, and furtherly enforce the development of national security and national defense.