Millimeter-Wave Massive MIMO Testbed with Hybrid Beamforming

TL;DR

This paper introduces a real-time 28 GHz massive MIMO testbed with hybrid beamforming, demonstrating cost-effective and scalable hardware for millimeter-wave communications.

Contribution

It presents a novel, modular hybrid beamforming testbed for mmWave massive MIMO, extending existing sub-6 GHz systems to higher frequencies.

Findings

Real-time operation at 28 GHz demonstrated

Modular design allows expansion to larger arrays

Supports testing of algorithms and scheduling in real environments

Abstract

Massive multiple-input multiple-out (MIMO) technology is vital in millimeter-wave (mmWave) bands to obtain large array gains. However, there are practical challenges, such as high hardware cost and power consumption in such systems. A promising solution to these problems is to adopt a hybrid beamforming architecture. This architecture has a much lower number of transceiver (TRx) chains than the total antenna number, resulting in cost- and energy-efficient systems. In this paper, we present a real-time mmWave (28 GHz) massive MIMO testbed with hybrid beamforming. This testbed has a 64-antenna/16-TRx unit for beam-selection, which can be expanded to larger array sizes in a modular way. For testing everything from baseband processing algorithms to scheduling and beam-selection in real propagation environments, we extend the capability of an existing 100-antenna/100-TRx massive MIMO testbed (below 6 GHz), built upon software-defined radio technology, to a flexible mmWave massive MIMO system.