Energy-Efficient Design for Downlink Pinching-Antenna Systems with QoS Guarantee

2025-05-20

AI Summary

This paper investigates energy efficiency (EE) maximization in a TDMA-based downlink multi-user system subject to per-user minimum rate constraints. To this end, it proposes the first joint optimization framework incorporating the physical positions of tunable-pinched antennas—alongside transmit power and time-slot allocation—as design variables, leveraging a single waveguide architecture. A decomposition-based iterative algorithm is developed, grounded in feasibility analysis and augmented with semi-analytical techniques to efficiently solve the resulting non-convex optimization problem. A channel reconstruction model tailored to pinched antennas is also established. Numerical results demonstrate that the proposed three-dimensional co-design—integrating antenna placement, power control, and temporal scheduling—significantly outperforms benchmark schemes with fixed or suboptimally positioned antennas, thereby validating both the efficacy and superiority of spatial–power–temporal coordination for EE enhancement.

Technology Category

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

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems

Abstract

Pinching antennas have recently garnered significant attention due to their ability to dynamically reconfigure wireless propagation environments. Despite notable advancements in this area, the exploration of energy efficiency (EE) maximization in pinching-antenna systems remains relatively underdeveloped. In this paper, we address the EE maximization problem in a downlink time-division multiple access (TDMA)-based multi-user system employing one waveguide and multiple pinching antennas, where each user is subject to a minimum rate constraint to ensure quality-of-service. The formulated optimization problem jointly considers transmit power and time allocations as well as the positioning of pinching antennas, resulting in a non-convex problem. To tackle this challenge, we first obtain the optimal positions of the pinching antennas. Based on this, we establish a feasibility condition for the system. Subsequently, the joint power and time allocation problem is decomposed into two subproblems, which are solved iteratively until convergence. Specifically, the power allocation subproblem is addressed through an iterative approach, where a semi-analytical solution is obtained in each iteration. Likewise, a semi-analytical solution is derived for the time allocation subproblem. Numerical simulations demonstrate that the proposed pinching-antenna-based strategy significantly outperforms both conventional fixed-antenna systems and other benchmark pinching-antenna schemes in terms of EE.

Problem

• Maximize energy efficiency in downlink pinching-antenna systems
• Ensure QoS with minimum rate constraints per user
• Optimize joint power, time allocation, and antenna positioning

Innovation

• Optimizes pinching antenna positions dynamically
• Decomposes joint power and time allocation iteratively
• Ensures QoS with semi-analytical solutions