Multi-User Symbol Detection with XL Reception: Dynamic Metasurface Antennas with Low Resolution ADCs

TL;DR

This paper proposes a joint design for hybrid analog/digital combiners in XL DMA receivers with low-resolution ADCs, enabling accurate multi-user symbol detection while balancing hardware complexity and performance.

Contribution

It introduces an efficient joint design method for hybrid A/D combiners in XL DMA systems with low-resolution ADCs, addressing non-convex optimization challenges.

Findings

XL DMA receivers achieve high-accuracy multi-user symbol detection.

Trade-offs exist between hardware complexity and MSE performance.

The proposed design outperforms existing methods in simulations.

Abstract

Dynamic Metasurface Antennas (DMAs) have been recently proposed as a cost- and energy-efficient front-end solution for eXtremely Large (XL) antenna array systems, supporting scalable Analog and Digital (A/D) beamforming while using a reduced number of Radio-Frequency (RF) chains. This array architecture is commonly realized as partially connected hybrid A/D beamformers, in which non-overlapping subarrays are linked to separate RF chains, each attached to a waveguide hosting multiple metamaterials. In this work, we study uplink multi-user communications where each RF chain of an XL DMA receiver is equipped with a $b$-bit resolution Analog-to-Digital Converter (ADC). We cast a Mean Squared Error (MSE) minimization problem for the design of the hybrid A/D combiner aimed at multi-user symbol detection, which is intrinsically non-convex due to the structural constraints imposed by the DMA hardware. By exploiting the Bussgang decomposition and a tractable modeling framework, we propose an efficient joint design of the hybrid A/D combining parameters. Our numerical evaluations showcase that XL DMA receivers can perform highly accurate multi-user symbol detection, revealing attractive trade-offs between hardware complexity and MSE performance.