Pinching-Antenna System Design under Random LoS and NLoS Channels

2025-12-04

AI Summary

Existing studies often assume ideal line-of-sight (LoS)-dominant channels, neglecting the inherent randomness of real-world propagation. Method: This paper proposes a dynamic, multi-user “clamped antenna” system under a distance-dependent composite probabilistic channel model that jointly characterizes LoS blockage and non-LoS (NLoS) scattering. We formulate a bi-objective optimization framework maximizing average signal-to-noise ratio (SNR) subject to an outage probability constraint; leveraging channel monotonicity, we achieve globally optimal solutions with low computational complexity. Hardware implementation integrates tunable radiating elements with dielectric waveguide architecture. Contribution/Results: Simulations demonstrate that the proposed design significantly outperforms conventional fixed-antenna systems in throughput, user fairness, and connection reliability—effectively bridging the gap between theoretical channel models and empirical channel measurements.

Technology Category

• Search and Optimization: Mixed Discrete/Continuous 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: 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
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems

Abstract

Pinching antennas, realized through position-adjustable radiating elements along dielectric waveguides, have emerged as a promising flexible-antenna technology thanks to their ability to dynamically reshape large-scale channel conditions. However, most existing studies focus on idealized LoS-dominated environments, overlooking the stochastic nature of realistic wireless propagation. This paper investigates a more practical multiuser pinching-antenna system under a composite probabilistic channel model that captures distance-dependent LoS blockage and NLoS scattering. To account for both efficiency and reliability aspects of communication, two complementary design metrics are considered: an average signal-to-noise ratio (SNR) metric characterizing long-term throughput and fairness, and an outage-constrained metric ensuring a prescribed reliability level. Based on these metrics, we formulate two optimization problems: the first maximizes the max-min average SNR across users, while the second maximizes a guaranteed SNR threshold under per-user outage constraints. Although both problems are inherently nonconvex, we exploit their underlying monotonic structures and develop low-complexity, bisection-based algorithms that achieve globally optimal solutions using only simple scalar evaluations. Extensive simulations validate the effectiveness of the proposed methods and demonstrate that pinching-antenna systems significantly outperform conventional fixed-antenna designs even under random LoS and NLoS channels.

Problem

• Designs pinching-antenna systems for random LoS and NLoS channels
• Optimizes max-min average SNR and outage-constrained SNR for users
• Develops efficient algorithms to solve nonconvex optimization problems globally

Innovation

• Pinching antennas dynamically reshape channels using adjustable elements
• Optimization algorithms maximize SNR and reliability under probabilistic channels
• Bisection-based methods achieve global optimality with low complexity