Optimal waveguide layouts improve pinching-antenna communication performance

Waveguide Deployment Optimization for Pinching-Antenna Systems

Information Theory

Summary

This paper looks at the best ways to place waveguides in systems that use pinching antennas to send signals. Instead of always positioning waveguides parallel to each other along one side of a service area, the authors find conditions when this layout is best and when other arrangements work better. They provide mathematical formulas and algorithms to decide how to place one or many waveguides to get the best communication results over time. Their work shows that sometimes nonparallel layouts help, especially at medium heights, while other arrangements are better in different cases.

What this means in practice

Authors

Yanqing Xu, Zhiguo Ding, Xiu Yin Zhang, Tsung-Hui Chang

Abstract

Most existing studies on pinching-antenna systems optimize the antenna positions or activation states under a prescribed waveguide deployment, where mutually parallel waveguides are commonly adopted. However, it remains unclear whether, and under what conditions, such a deployment is optimal from a communication-performance perspective. To fill this gap, this paper investigates long-term waveguide deployment optimization for pinching-antenna systems over a rectangular service region. We first consider the fundamental two-waveguide case and derive a closed-form sufficient condition, jointly determined by the waveguide height and the service-region aspect ratio, under which a deployment parallel to the longer side of the service region is globally optimal. We then consider the general multi-waveguide case, where the orientation and offset of each waveguide are jointly optimized without prescribing any deployment pattern, and develop an adaptive exchange algorithm for the resulting nonconvex optimization problem. We further show that, within the parallel class, the waveguides should be aligned with the longer side of the service region, while in the large-height regime, the globally optimal unrestricted deployment asymptotically concentrates all waveguides on the centerline along the longer side. Numerical results validate the proposed algorithm and reveal how the preferred deployment geometry depends on the waveguide height and service-region shape. In particular, nonparallel deployments can provide noticeable gains in intermediate-height regimes, whereas parallel or center-concentrated deployments become favorable in other regimes.