Dual-Scale Antenna Deployment for Pinching Antenna Systems
Xu Gan, Zhaolin Wang, Yuanwei Liu
TL;DR
This work tackles energy-efficient PA deployment for PASS by introducing a dual-scale deployment (DSD) framework that separates coarse base sliding from fine PA tuning. It develops four deployment protocols STT, STA, SAT, and SAA and a practical power-consumption model, deriving the energy-efficiency metric $\eta_{EE} = \frac{B \sum_{k} R_k}{P_{all}}$ under the framework. A penalty-based alternating optimization algorithm is proposed to jointly optimize transmit precoding $\mathbf{W}$, PA radiation $\bm{\Xi}$, and PA positions $\mathbf{X}$, using Lagrange duality, Riemannian manifold optimization, and two-stage grid searches. Numerical results show PASS achieving about $70\%$ EE gain over conventional cell-free and nearly $2\times$ gain over MIMO, with EE highly sensitive to DSD resolution and the deployment protocol chosen. The study provides a practical roadmap for energy-efficient dual-scale PA deployment in PASS and highlights directions for protocol design and dual-scale channel estimation.
Abstract
A dual-scale deployment (DSD) framework for pinching antenna systems (PASS) is proposed. 1) In the first coarse stage, the pinching antenna (PA) is transferred over a large-scale range at the waveguide level. 2) The refinement stage performs small-scale relocation of the PA with high precision. Four PA deployment protocols are provided in the proposed DSD framework. Then, a practical power consumption model is proposed, based on which the theoretical energy efficiency formulas for PASS are derived. The transmit precoding, PA radiation power, and PA deployment are jointly optimized to maximize the energy efficiency under the provided PA deployment protocols. To solve this non-convex, highly coupled problem, a low-complexity penalty-based alternating optimization algorithm is proposed. Simulation results validate the accuracy of theoretical results and the convergence of the proposed algorithm. It is demonstrated that: 1) PASS delivers about 70% higher energy efficiency than the conventional cell-free architecture and nearly twofold improvement relative to MIMO systems; 2) it is essential to specify the DSD resolution and deployment protocol to achieve the maximum energy efficiency for PASS.
