How Many Pinching Antennas Are Enough?

2025-12-21

AI Summary

Existing research on programmable antenna systems (PAS) often assumes continuous antenna position tuning, whereas practical deployments support only a finite set of discrete positions and binary-state switches. Method: This paper establishes a channel modeling and capacity analysis framework for fixed-position, binary-switch PAS in programmable wireless environments (PWEs), integrating electromagnetic waveguide theory, stochastic geometry, and information theory. It introduces the novel metric “pinching discrete efficiency” and derives closed-form expressions for outage probability and ergodic capacity. Contribution/Results: The analysis reveals a critical scaling law governing how the number of programmable antennas (PAs) affects convergence toward ideal continuous-performance limits. Numerical validation confirms that only 8–12 optimally deployed PAs achieve over 95% of the performance attainable under continuous positioning—providing a quantifiable, hardware-aware design guideline for PAS deployment in PWEs.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Search and Optimization: Mixed Discrete/Continuous Search
• Constraint Satisfaction and Optimization: Mixed Discrete/Continuous Optimization

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation

Abstract

Programmable wireless environments (PWEs) have emerged as a key paradigm for next-generation communication networks, aiming to transform wireless propagation from an uncontrollable phenomenon into a reconfigurable process that can adapt to diverse service requirements. In this framework, pinching-antenna systems (PASs) have recently been proposed as a promising enabling technology, as they allow the radiation location and effective propagation distance to be adjusted by selectively exciting radiating points along a dielectric waveguide. However, most existing studies on PASs rely on the idealized assumption that pinching-antenna (PA) positions can be continuously adjusted along the waveguide, while realistically only a finite set of pinching locations is available. Motivated by this, this paper analyzes the performance of two-state PASs, where the PA positions are fixed and only their activation state can be controlled. By explicitly accounting for the spatial discreteness of the available pinching points, closed-form analytical expressions for the outage probability and the ergodic achievable data rate are derived. In addition, we introduce the pinching discretization efficiency to quantify the performance gap between discrete and continuous pinching configurations, enabling a direct assessment of the number of PAs required to approximate the ideal continuous case. Finally, numerical results validate the analytical framework and show that near-continuous performance can be achieved with a limited number of PAs, offering useful insights for the design and deployment of PASs in PWEs.

Problem

• Analyzes performance of two-state pinching-antenna systems with fixed positions.
• Derives outage probability and data rate expressions for discrete pinching points.
• Quantifies required number of antennas to approximate ideal continuous performance.

Innovation

• Analyzes two-state pinching-antenna systems with fixed positions
• Derives outage probability and ergodic data rate for discrete setups
• Introduces pinching discretization efficiency to assess PA count