CAPA: Continuous-Aperture Arrays for Revolutionizing 6G Wireless Communications

TL;DR

This paper introduces a novel continuous-aperture array (CAPA) architecture for 6G wireless communications, highlighting its design, implementation, and performance advantages over traditional arrays.

Contribution

It proposes new hardware approaches and beamforming techniques for CAPAs, demonstrating their potential to significantly enhance wireless communication performance.

Findings

CAPA offers higher channel capacity than traditional arrays.

Beamforming approaches improve efficiency and near-optimality.

Numerical results show CAPA's advantages in diversity-multiplexing gains.

Abstract

In this paper, a novel continuous-aperture array (CAPA)-based wireless communication architecture is proposed, which relies on an electrically large aperture with a continuous current distribution. First, an existing prototype of CAPA is reviewed, followed by the potential benefits and key motivations for employing CAPAs in wireless communications. Then, three practical hardware implementation approaches for CAPAs are introduced based on electronic, optical, and acoustic materials. Furthermore, several beamforming approaches are proposed to optimize the continuous current distributions of CAPAs, which are fundamentally different from those used for conventional spatially discrete arrays (SPDAs). Numerical results are provided to demonstrate their key features in low complexity and near-optimality. Based on these proposed approaches, the performance gains of CAPAs over SPDAs are revealed in terms of channel capacity as well as diversity-multiplexing gains. Finally, several open research problems in CAPA are highlighted.