标题： 具有波导内衰减的夹钳天线系统：性能分析与算法设计 显示英文标题

标题： Pinching-Antenna Systems with In-Waveguide Attenuation: Performance Analysis and Algorithm Design

摘要： 夹钳天线系统已成为下一代无线网络中一种有前途的柔性天线架构，通过在波导上重新定位天线，实现了增强的适应性和以用户为中心的连接。 然而，现有研究常常忽视波导内的信号衰减，在文献中，尚无对这种假设是否成立以及在何种条件下成立的全面分析。 本文通过将波导内衰减明确纳入系统模型和算法设计，并研究其对下行链路用户数据速率的影响，解决了这一差距。 我们首先从单用户场景开始，推导出全局最优天线位置的闭式表达式，该表达式揭示了衰减系数和用户到波导距离如何共同影响最优天线位置。 基于此解析解，我们进一步提供了理论分析，确定了波导内衰减对用户可实现速率影响不显著的系统条件。 随后，该研究扩展到多用户多输入多输出设置，在此情况下，开发了两种高效的算法，基于加权最小均方误差方法和最大比合并方法，以联合优化波束成形和天线位置。 仿真结果验证了所提出算法的有效性，并表明夹钳天线系统明显优于传统的固定天线基线，突显了其在未来的柔性无线通信中的潜力。 显示英文摘要

摘要： Pinching-antenna systems have emerged as a promising flexible-antenna architecture for next-generation wireless networks, enabling enhanced adaptability and user-centric connectivity through antenna repositioning along waveguides. However, existing studies often overlook in-waveguide signal attenuation and in the literature, there is no comprehensive analysis on whether and under what conditions such an assumption is justified. This paper addresses this gap by explicitly incorporating in-waveguide attenuation into both the system model and algorithm design, and studying its impact on the downlink user data rates. We begin with a single-user scenario and derive a closed-form expression for the globally optimal antenna placement, which reveals how the attenuation coefficient and the user-to-waveguide distance jointly affect the optimal antenna position. Based on this analytical solution, we further provide a theoretical analysis identifying the system conditions under which the in-waveguide attenuation has an insignificant impact on the user achievable rate. The study is then extended to the multi-user multiple-input multiple-output setting, where two efficient algorithms are developed, based on the weighted minimum mean square error method and the maximum ratio combining method, to jointly optimize beamforming and antenna placement. Simulation results validate the efficacy of the proposed algorithms and demonstrate that pinching-antenna systems substantially outperform conventional fixed-antenna baselines, underscoring their potential for future flexible wireless communications.