Low-Complexity Distance-Based Scheduling for Multi-User XL-MIMO Systems

TL;DR

This paper presents DBS, a low-complexity user selection method for XL-MIMO systems that effectively manages interference and maintains high performance, even with realistic propagation models, enabling more users to be served.

Contribution

Introduces DBS, a novel user selection technique based on user distance categorization that reduces complexity while maintaining performance in XL-MIMO systems.

Findings

DBS matches zero-forcing beamforming performance with lower complexity

A simplified DBS performs well under spherical-wavefront propagation

SW propagation increases the number of users that can be served

Abstract

We introduce DBS, a new technique for user selection in downlink multi-user communications with extra-large (XL) antenna arrays. DBS categorizes users according to their equivalent distance to the antenna array. Such categorization effectively accounts for inter-user interference while largely reducing the computational burden. Results show that (i) DBS achieves the same performance as the reference zero-forcing beamforming scheme with a lower complexity; (ii) a simplified version of DBS achieves a similar performance when realistic spherical-wavefront (SW) propagation features are considered; (iii) SW propagation brings additional degrees of freedom, which allows for increasing the number of served users.