Hardware-Aware Beamspace Precoding for All-Digital mmWave Massive MU-MIMO

TL;DR

This paper introduces a hardware-efficient beamspace precoding method for mmWave massive MU-MIMO systems, significantly reducing complexity while maintaining near-optimal error-rate performance.

Contribution

It proposes a two-stage beamspace precoding architecture that simplifies hardware implementation for all-digital mmWave MU-MIMO systems.

Findings

Approaches the error-rate of Wiener filter precoding

Achieves over 2x reduction in complexity

Enables regular hardware architectures for precoding

Abstract

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.