π€ AI Summary
This work addresses the coverage limitations of conventional pinching-antenna systems in high-frequency wireless communications, which stem from dielectric waveguide attenuation and wired interconnection constraints. To overcome these challenges, the authors propose a wireless-fed pinching-antenna architecture that employs a full-duplex amplify-and-forward relay equipped with a highly directional horn antenna between the base station and the waveguide entrance. The system jointly optimizes antenna placement, relay gain, and transmit power. By introducing, for the first time, a wireless feeding mechanism combined with a full-duplex relay structure, the design eliminates the need for wired connections and derives closed-form optimal solutions for the aforementioned parameters. The proposed scheme significantly reduces total power consumption while enhancing high-frequency link budget and coverage performance under stringent user quality-of-service requirements, outperforming both non-relay and fixed-antenna relay baselines.
π Abstract
Pinching-antenna systems have recently emerged as a promising solution for enhancing coverage in high-frequency wireless communications by guiding signals through dielectric waveguides and radiating them via position-adjustable antennas. However, their practical deployment is fundamentally constrained by waveguide attenuation and line-installation requirements, which limit the achievable coverage range. To address this challenge, this paper investigates a wireless-fed pinching-antenna architecture that employs highly directional horn antennas to enable efficient coverage extension. Specifically, a full-duplex amplify-and-forward relay equipped with horn antennas is introduced between the base station and the waveguide input, which significantly improves the link budget in high-frequency bands while effectively eliminating self-interference. On this basis, we formulate a total power minimization problem subject to a quality-of-service constraint at the user equipment, involving the joint optimization of the pinching-antenna position, the relay amplification gain, and the base station transmit power. By exploiting the structure of the end-to-end signal-to-noise ratio, the optimal pinching-antenna position is first obtained in closed form by balancing waveguide attenuation and free-space path loss. Subsequently, closed-form expressions for the optimal relay gain and transmit power are derived. Numerical results demonstrate that the proposed scheme substantially outperforms conventional systems without relaying and relay-assisted transmission with fixed antennas in terms of total power consumption.