Programmable wireless environments (PWEs) represent a central paradigm in next-generation communication networks, aiming to transform wireless propagation from a passive medium into an intelligent and reconfigurable entity capable of dynamically adapting to network demands. In this context, pinching-antenna systems (PASs) have emerged as a promising enabler capable of reconfiguring both the channel characteristics and the path loss itself by selectively exciting radiation points along dielectric waveguides. However, existing studies largely rely on the assumption of continuously reconfigurable pinching antenna (PA) positions, overlooking the discreteness imposed by practical implementations, which allow for only a finite number of PA position. In this paper, an analytical framework is developed for evaluating the rate performance of two-state PASs, where the antenna locations are fixed, and only their activation states can be controlled. The analysis incorporates the discrete spatial structure of the waveguide and leads to a closed-form expression for the ergodic achievable data rate, while pinching discretization efficiency is introduced to quantify the performance deviation from the ideal continuous configuration. Simulation results demonstrate that near-continuous performance can be achieved with a limited number of PAs, offering valuable insights into the design and scalability of PASs in PWEs.

翻译：可编程无线环境（PWEs）代表了下一代通信网络的核心范式，旨在将无线传播从被动媒介转变为能够根据网络需求动态调整的智能可重构实体。在此背景下，夹持天线系统（PASs）作为一种有前景的使能技术应运而生，它能够通过选择性激发介质波导上的辐射点来重构信道特性及路径损耗本身。然而，现有研究大多基于夹持天线（PA）位置可连续重构的假设，忽略了实际实现中仅允许有限数量PA位置所施加的离散性。本文针对双态PAS开发了一个分析框架，其中天线位置固定，仅其激活状态可控。该分析结合了波导的离散空间结构，推导出遍历可达数据速率的闭式表达式，同时引入夹持离散化效率以量化其与理想连续配置的性能偏差。仿真结果表明，有限数量的PA即可实现接近连续的性能，为PWEs中PAS的设计与可扩展性提供了重要参考。