基于雷达波形和压缩感知核联合优化的Sub-Nyquist认知雷达

认知雷达和宽带/超宽带雷达是雷达研究的两个重要方面，是抑制杂波、电磁干扰/电子对抗信号和实现目标精细化测量的重要途径。然而，模数转换器的发展水平极大地限制了大带宽雷达信号的使用和后续信号处理。本申请提出将压缩感知理论应用于认知雷达，采用模信转换获取Sub-Nyquist率雷达回波信号，发展Sub-Nyquist认知雷达信号处理技术。与传统认知雷达不同，Sub-Nyquist认知雷达采样信号不仅包含雷达回波信息，同时与模信转换结构密切相关。为此，本申请提出雷达发射波形和压缩感知核联合优化的设计思想，以有效获取环境和目标信息。这种设计与传统认知雷达只设计雷达波形有很大的差别。本申请研究内容主要包括Sub-Nyquist率的环境信息感知、雷达波形和压缩感知核联合优化设计、目标信息估计等。除外，本申请还将基于正交压缩采样模信转换，设计和实现Sub-Nyquist认知雷达原理系统，验证其性能。

Cognitive radar and wideband/ultra-wideband radar are two kinds of important radar systems. They have strong capability to reject radar clutter and jamming/electronic counter-measure interferences, and can implement accurate and high-resolution measurements of radar targets. However, current analog-to-digital conversion limits the application of wideband/ultra-wideband radar signals and subsequent signal processing. This proposal incorporates compressive sensing theory into the design of cognitive radars and proposes the concept of sub-Nyquist cognitive radar with digital acquisition of radar echoes by analog-to-information conversion at sub-Nyquist rate. The aim of the study is to develop a framework of the sub-Nyquist cognitive radar and the corresponding intelligent signal processing. Different from traditional cognitive radar, the samples of the proposed sub-Nyquist cognitive radar echoes not only contain the information of radar targets, but also depend closely on the analog-to-information conversion system. To efficiently acquire the information of radar environments and targets, the proposal develops a joint optimization design of radar waveforms and compressive sensing kernels, which is different from the design on radar waveforms only in traditional cognitive radar. The research scopes mainly include the sub-Nyquist sampling-based environment information sensing, the optimization and design of the radar waveform and the sensing kernel, the sub-Nyquist sampling-based target information estimation and so on. Moreover, to evaluate the performance of the proposed sub-Nyquist cognitive radar, the proposal will develop a prototype system with the quadrature compressive sampling system developed in our lab.