Massive multi-user multiple-input multiple-output (MU-MIMO) wireless systems operating at millimeter-wave (mmWave) frequencies enable simultaneous wideband data transmission to a large number of users. In order to reduce the complexity of MU precoding in all-digital basestation architectures, we propose a two-stage precoding architecture that first performs precoding using a sparse matrix in the beamspace domain, followed by an inverse fast Fourier transform that converts the result to the antenna domain. The sparse precoding matrix requires a small number of multipliers and enables regular hardware architectures, which allows the design of hardware-efficient all-digital precoders. Simulation results demonstrate that our methods approach the error-rate of conventional Wiener filter precoding with more than 2x reduced complexity.
@article{arxiv.2108.06229,
title = {Hardware-Aware Beamspace Precoding for All-Digital mmWave Massive MU-MIMO},
author = {Emre Gönültaş and Sueda Taner and Alexandra Gallyas-Sanhueza and Seyed Hadi Mirfarshbafan and Christoph Studer},
journal= {arXiv preprint arXiv:2108.06229},
year = {2021}
}