基于夹捏天线的安全近场ISAC：利用相长-相消干涉
Secure Near-Field ISAC with Pinching-Antenna Systems: Exploiting Constructive-Destructive Interference
- Aristotle University of Thessaloniki（塞萨洛尼基亚里士多德大学）
- Friedrich-Alexander-Universität Erlangen-Nürnberg（埃尔朗根-纽伦堡弗里德里希·亚历山大大学）
- University College London（伦敦大学学院）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文针对夹捏天线系统下的安全近场ISAC，联合设计符号级预编码和天线位置，利用相长/相消干涉实现可靠通信与目标定位，并提出了高效优化算法，实现亚毫米级定位和显著性能提升。
AI中文摘要：
本文研究了采用夹捏天线系统（PASS）的安全近场集成感知与通信（ISAC），其中基站服务合法用户，同时对可能窃听传输数据的目标进行定位。我们联合设计了符号级预编码（SLP）以及发射和接收夹捏天线位置，以最小化数据符号上的笛卡尔位置误差界（PEB）平均值。相长干涉确保合法用户的可靠接收，而相消干涉将目标的观测推向错误的符号区域，同时不牺牲感知所需的照明。我们推导了未知复目标反射率下的PEB，并建立了发射照明项和接收几何项的精确分解。该分解揭示了两个孔径的不同感知作用，使得接收位置优化和联合发射位置/SLP优化可以分别进行，并为局部位置可辨识性、紧凑阵列的测距信息限制、面向感知的接收位置以及波导内衰减提供了分析见解。基于这些结果，我们开发了一种高效算法，结合了几何信息接收初始化、一维发射位置搜索和凸逐符号预编码。数值结果展示了亚毫米级定位、目标处的错误符号决策、扩展的可行工作区域，以及相对于固定位置PASS和全数字超大规模MIMO（XL-MIMO）基准的显著性能提升。
英文摘要：
This paper investigates secure near-field integrated sensing and communication (ISAC) with pinching-antenna systems (PASS), where a base station serves legitimate users while localizing a target that may also eavesdrop on the transmitted data. We jointly design symbol-level precoding (SLP) and the transmit and receive pinching-antenna positions to minimize the Cartesian position error bound (PEB) averaged over the data symbols. Constructive interference ensures reliable reception at the legitimate users, whereas destructive interference drives the target's observation toward incorrect symbol regions without sacrificing the illumination required for sensing. We derive the PEB for unknown complex target reflectivity and establish an exact factorization into transmit-illumination and receive-geometry terms. This decomposition reveals the distinct sensing roles of the two apertures, enables separate receive-placement and joint transmit-placement/SLP optimization, and provides analytical insights into local position identifiability, the range-information limitations of compact arrays, sensing-oriented receive placement, and in-waveguide attenuation. Building on these results, we develop an efficient algorithm by combining geometry-informed receive initialization, one-dimensional transmit-position searches, and convex per-symbol precoding. Numerical results demonstrate sub-millimeter localization, erroneous symbol decisions at the target, an expanded feasible operating region, and substantial gains over fixed-placement PASS and fully digital extremely large-scale MIMO (XL-MIMO) benchmarks.
