This paper investigates the spectrum sharing between a multiple-input single-output (MISO) secure communication system and a multiple-input multiple-output (MIMO) radar system in the presence of one suspicious eavesdropper. We jointly design the radar waveform and communication beamforming vector at the two systems, such that the interference between the base station (BS) and radar is reduced, and the detrimental radar interference to the communication system is enhanced to jam the eavesdropper, thereby increasing secure information transmission performance. In particular, by considering the imperfect channel state information (CSI) for the user and eavesdropper, we maximize the worst-case secrecy rate at the user, while ensuring the detection performance of radar system. To tackle this challenging problem, we propose a two-layer robust cooperative algorithm based on the S-lemma and semidefinite relaxation techniques. Simulation results demonstrate that the proposed algorithm achieves significant secrecy rate gains over the non-robust scheme. Furthermore, we illustrate the trade-off between secrecy rate and detection probability.

翻译：本文研究存在可疑窃听者时，多输入单输出（MISO）安全通信系统与多输入多输出（MIMO）雷达系统之间的频谱共享问题。我们联合设计两个系统的雷达波形与通信波束赋形向量，以降低基站与雷达之间的干扰，同时增强对通信系统有害的雷达干扰以压制窃听者，从而提高安全信息传输性能。特别地，考虑用户和窃听者信道状态信息（CSI）不完美的情况，我们最大化用户在雷达系统检测性能保障下的最坏情况安全速率。为求解该具有挑战性的问题，我们提出一种基于S引理与半定松弛技术的两层鲁棒协同算法。仿真结果表明，所提算法相比非鲁棒方案实现了显著的安全速率增益。此外，我们进一步揭示了安全速率与检测概率之间的权衡关系。