Pinching-Antenna-based Communications: Spectral Efficiency Analysis and Deployment Strategies

2025-07-20

AI Summary

This paper addresses spectral efficiency (SE) optimization in multi-waveguide-pinned antenna (PA) multi-user communication systems. It comparatively analyzes two deployment strategies: centralized (time-division switching plus beamforming gain) versus distributed (spatial-division multiplexing with concurrent transmission). A unified analytical framework is proposed, leveraging maximum-ratio transmission precoding and the method of stationary phase to derive closed-form SE expressions. Key findings include an SE performance reversal between regimes: the distributed strategy outperforms the centralized one at high SNR, whereas the opposite holds at low SNR. Furthermore, large waveguide spacing is shown to effectively suppress inter-user interference—establishing a novel design principle for PA systems. Theoretical analysis is corroborated by simulations, providing quantifiable, implementation-guiding insights for practical system deployment.

Technology Category

• Search and Optimization: Distributed Search
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Constraint Satisfaction and Optimization: Distributed CSP/Optimization

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• Security and Privacy: Large-scale security measurements
• Search and Retrieval-Augmented AI: Efficiency and scalability of Web search engines

Abstract

A multiple-waveguide pinching-antenna (PA)-based multi-user communication system is investigated. With a given number of PAs, two deployment strategies are considered, namely the centralized PA deployment, where all PAs are switched between waveguides to serve users in a time-division manner to avail of beamforming gain, and the distributed PA deployment, where a single PA is deployed on each waveguide to simultaneously serve multiple users by leveraging the multiplexing gain. The spectral efficiency (SE) achieved by each deployment strategy is analyzed: i) For the centralized deployment, the positioning strategy of PAs on each waveguide is determined first with the aim of maximizing the channel gain of the corresponding nearest served user. Based on this, the corresponding system SE is derived. ii) For the distributed deployment, the system SE under the maximum ratio transmission (MRT) is first obtained. To obtain an analytically tractable form, the stationary phase method is utilized to approximate the system SE. The approximation result reveals that the average inter-user interference can be negligible with a large waveguide spacing and thus the simple MRT is appealing for PA-based multi-user communications. Furthermore, the system SEs achieved by the two strategies are compared in both the high and low signal-to-noise ratio (SNR) regimes. Our analysis suggests that at high SNRs, the distributed deployment is superior to achieve the maximal system SE, while the centralized deployment is more suitable for the low-SNR regime. Finally, the theoretical analysis is verified through simulations.

Problem

• Analyzes spectral efficiency of pinching-antenna deployment strategies
• Compares centralized vs distributed PA deployment for multi-user systems
• Determines optimal deployment based on SNR regimes and interference

Innovation

• Multiple-waveguide pinching-antenna system for multi-user communication
• Centralized PA deployment maximizes beamforming gain via time-division
• Distributed PA deployment leverages multiplexing gain for simultaneous users