Modern radar systems are expected to operate reliably in congested environments. A candidate technology for meeting these demands is frequency agile radar (FAR), which randomly changes its carrier frequencies. FAR is known to improve the electronic counter-countermeasures (ECCM) performance while facilitating operation in congested setups. To enhance the target recovery performance of FAR in complex electromagnetic environments, we propose two radar schemes extending FAR to multi-carrier waveforms. The first is Wideband Multi-carrier Agile Radar (WMAR), which transmits/receives wideband waveforms simultaneously with every antenna. To mitigate the demanding hardware requirements associated with wideband waveforms used by WMAR, we next propose multi-Carrier AgilE phaSed Array Radar (CAESAR). CAESAR uses narrowband monotone waveforms, thus facilitating ease of implementation of the system, while introducing spatial agility. We characterize the transmitted and received signals of the proposed schemes, and develop an algorithm for recovering the targets, based on concepts from compressed sensing to estimate the range-Doppler parameters of the targets. We then derive conditions which guarantee their accurate reconstruction. Our numerical study demonstrates that both multi-carrier schemes improve performance compared to FAR while maintaining its practical benefits. We also demonstrate that the performance of CAESAR, which uses monotone waveforms, is within a small gap from the wideband radar.

中文翻译：

---

多载波敏捷相控阵雷达

现代雷达系统有望在拥挤的环境中可靠地运行。满足这些需求的一种候选技术是频率捷变雷达 (FAR)，它随机改变其载波频率。众所周知，FAR 可以提高电子对抗 (ECCM) 性能，同时促进拥挤设置中的操作。为了提高复杂电磁环境中 FAR 的目标恢复性能，我们提出了两种将 FAR 扩展到多载波波形的雷达方案。第一个是宽带多载波敏捷雷达 (WMAR)，它与每个天线同时发送/接收宽带波形。为了减轻与 WMAR 使用的宽带波形相关的苛刻硬件要求，我们接下来提出了多载波敏捷相控阵雷达 (CAESAR)。CAESAR 使用窄带单调波形，从而促进系统的轻松实施，同时引入空间敏捷性。我们表征了所提出方案的发射和接收信号，并基于压缩感知的概念开发了一种用于恢复目标的算法，以估计目标的距离多普勒参数。然后我们推导出保证它们准确重建的条件。我们的数值研究表明，与 FAR 相比，这两种多载波方案都提高了性能，同时保持了其实际优势。我们还证明了使用单调波形的 CAESAR 的性能与宽带雷达的差距很小。并基于压缩感知的概念开发一种用于恢复目标的算法，以估计目标的距离多普勒参数。然后我们推导出保证它们准确重建的条件。我们的数值研究表明，与 FAR 相比，这两种多载波方案都提高了性能，同时保持了其实际优势。我们还证明了使用单调波形的 CAESAR 的性能与宽带雷达的差距很小。并基于压缩感知的概念开发一种用于恢复目标的算法，以估计目标的距离多普勒参数。然后我们推导出保证它们准确重建的条件。我们的数值研究表明，与 FAR 相比，这两种多载波方案都提高了性能，同时保持了其实际优势。我们还证明了使用单调波形的 CAESAR 的性能与宽带雷达的差距很小。