An online frequency allocation strategy for multi‐carrier radar against spot jammer

Abstract Spot jamming poses a significant threat to radar detection due to its ability to rapidly intercept radar signals and emit high‐power interference. A novel Cognitive Multi‐Carrier Radar (CMCR) is proposed, which utilises a detection waveform comprising multiple narrow bands to reduce the disruption from the spot jammer. Additionally, it can analyse the target’s Radar Cross‐Section (RCS) characteristics and proactively select frequencies with high RCS for detection, thereby enhancing target detection capability. The online frequency allocation problem of CMCR is a Multi‐Armed Bandit (MAB) problem with a combinatorial action space. To tackle the challenge from the huge action space, an efficient aDaptive Accept Reject (DART) method is employed, which significantly reduces the regret of CMCR in the detection task. Moreover, a slide‐window change point indicator is proposed to monitor the change of target’s RCS, which enables CMCR to be applicable in scenarios where target’s RCS varies. Finally, the effectiveness and robustness of CMCR are through extensive numerical experiments.