1-bit Quantized Continuous Aperture Arrays

TL;DR

This paper explores the use of continuous aperture arrays with 1-bit ADCs in 6G systems, revealing their potential to outperform discrete arrays under certain conditions and providing analytical insights into their error performance.

Contribution

It introduces a novel analysis of CAPAs with 1-bit ADCs, deriving closed-form error probability approximations and demonstrating their advantages over discrete arrays.

Findings

CAPAs with 1-bit ADCs have a diversity-order penalty under Rayleigh fading.

Under LoS conditions, CAPAs can achieve the unquantized AWGN performance bound.

Monte Carlo simulations confirm the analytical error performance results.

Abstract

Continuous aperture arrays (CAPAs) have emerged as a promising physical-layer paradigm for sixth generation (6G) systems, offering spatial degrees of freedom beyond those of conventional discrete antenna arrays. This paper investigates the interaction between the CAPA receive architecture and low-cost 1-bit analog-to-digital converters (ADCs), which impose a severe nonlinear distortion penalty in conventional discrete systems. For Rayleigh fading, we derive a moment matching approximation (MMA)-based closed-form symbol error probability (SEP) approximation based on Gamma moment-matching of the spatial eigenvalue distribution, and show that CAPAs incur a diversity-order penalty governed by Jensen's inequality on the mode eigenvalues. For line-of-sight (LoS) propagation, we prove that CAPA achieves exactly the unquantized additive white Gaussian noise (AWGN) performance bound under perfect spatial and phase alignment, completely eliminating the 1-bit penalty that forces discrete systems to double their antenna count. Monte Carlo simulations under Rayleigh, Rician, and LoS conditions validate all analytical results.