Full-stack Hybrid Beamforming in mmWave 5G Networks

TL;DR

This paper investigates the complex interactions of hybrid beamforming, channel estimation, and MU-MIMO scheduling in mmWave 5G networks, revealing that joint multi-user beamforming significantly enhances throughput via SDMA.

Contribution

It provides a comprehensive analysis of full-stack interactions in mmWave 5G, emphasizing the importance of joint multi-user beamforming for optimal performance.

Findings

Joint multi-user beamforming is essential for maximizing MU-MIMO benefits.

Channel estimation schemes impact MU-MIMO scheduling effectiveness.

Throughput can be dramatically increased using SDMA in mmWave 5G.

Abstract

This paper analyzes Hybrid Beamforming (HBF) and Multi-User Multiple-Input Multiple-Output (MU-MIMO) in millimeter wave (mmWave) 5th generation (5G) cellular networks considering the full protocol stack with TCP/IP traffic and MAC scheduling. Prior work on HBF and MU-MIMO has assumed full-buffer transmissions and studied link-level performance. We report non-trivial interactions between the HBF technique, the front-loaded channel estimation pilot scheme in NR, and the constraints of MU-MIMO scheduling. We also report that joint multi-user beamforming design is imperative, in the sense that the MU-MIMO system cannot be fully exploited when implemented as a mere collection of single-user analog beams working in parallel. By addressing these issues, throughput can be dramatically increased in mmWave 5G networks by means of Spatial Division Multiple Access (SDMA).