Leaky-Coaxial Pinching-Antenna System with Adjustable Slot Apertures

TL;DR

This paper introduces an adjustable slot aperture system for leaky coaxial pinching antennas, enabling continuous control over aperture size to enhance wireless communication performance.

Contribution

It models aperture adjustment as channel amplitude scaling, deriving analytical performance gains and optimizing TDMA schemes for improved data rates.

Findings

Continuous aperture adjustment outperforms binary activation in sum rate.

The proposed system significantly reduces outage probability.

Optimization techniques effectively maximize sum rate in the system.

Abstract

As a practical physical implementation of pinching-antenna systems, leaky coaxial cable (LCX) enables distributed radiation in more general wireless environments, particularly for lower-frequency applications. In this paper, a leaky-coaxial pinching-antenna system, referred to as the LCX pinching-antenna system, is investigated, and adjustable slot apertures are introduced, such that the slot size can be continuously adjusted rather than being restricted to binary activation. Specifically, the aperture adjustment is modeled as amplitude scaling of the channels induced by the corresponding slots, or equivalently, as power coefficients associated with different slots. Accordingly, analytical results are derived to quantify the performance gain of continuous aperture adjustment over binary slot activation and to reveal the impact of channel coherence on the achievable data rate improvement. Furthermore, static and dynamic time-division multiple access (TDMA) schemes are considered, and the corresponding sum rate maximization problems are formulated and efficiently solved by quadratic transform based optimization, combined with successive convex approximation and alternating updates. Simulation results demonstrate that the proposed design can significantly outperform conventional fixed-antenna systems, traditional LCX schemes, and binary slot activation in terms of both achievable sum rate and outage probability.