In this work, we investigate a blockage-aware pinching antenna (PA) system designed for secure and robust wireless communication. The considered system comprises a base station equipped with multiple waveguides, each hosting multiple PAs, and serves multiple single-antenna legitimate users in the presence of multi-antenna eavesdroppers under imperfect channel state information (CSI). To safeguard confidential transmissions, artificial noise (AN) is deliberately injected to degrade the eavesdropping channels. Recognizing that conventional linear CSI error bounds become overly conservative for spatially distributed PA architectures, we develop new geometry aware uncertainty sets that jointly characterize eavesdropper position and array-orientation errors. Building upon these sets, we formulate a robust joint optimization problem that determines per waveguide beamforming and AN covariance, individual PA power ratio allocation, and PA positions to maximize the system sum rate subject to secrecy constraints. The highly nonconvex design problem is efficiently addressed via a low computational complexity iterative algorithm that capitalizes on block coordinate descent, penalty based methods, majorization minimization, the S procedure, and Lipschitz based surrogate functions. Simulation results demonstrate that the sum rate achieved by the proposed algorithm outperforms conventional fixed-antenna systems by 4.7 dB, offering substantially improved rate and secrecy performance. In particular, (i) adaptive PA positioning preserves LoS to legitimate users while effectively exploiting waveguide geometry to disrupt eavesdropper channels, and (ii) neglecting blockage effects in the PA system significantly impacts the system design, leading to performance degradation and inadequate secrecy guarantees.

翻译：本文研究了一种面向安全鲁棒无线通信的遮挡感知柔性天线系统。所考虑的系统包含一个配备多根波导的基站，每根波导上承载多个柔性天线，在非完美信道状态信息条件下，为多个单天线合法用户提供服务，同时存在多天线窃听者。为保障机密传输，系统主动注入人工噪声以恶化窃听信道。考虑到传统线性信道状态信息误差界对空间分布式柔性天线架构而言过于保守，本文提出了一种新的几何感知不确定集，该集合能联合表征窃听者位置和阵列朝向误差。基于此不确定集，我们构建了一个鲁棒联合优化问题，在满足保密约束条件下，确定每根波导的波束成形向量与人工噪声协方差矩阵、单个柔性天线的功率分配比及其位置，以最大化系统总速率。针对这一高度非凸的设计问题，我们提出了一种低计算复杂度的迭代算法，该算法融合了块坐标下降法、惩罚函数法、极大极小化方法、S-procedure以及基于Lipschitz的代理函数。仿真结果表明，该算法所实现的总速率相比传统固定天线系统提升了4.7 dB，在传输速率与保密性能方面均有显著改善。特别地：（i）自适应柔性天线定位能保持对合法用户的视距传输，同时有效利用波导几何结构破坏窃听者信道；（ii）若忽略遮挡效应，将严重影响柔性天线系统的设计，导致性能下降与保密性保障不足。