Finite-Alphabet Wiener Filter Precoding for mmWave Massive MU-MIMO Systems

TL;DR

This paper introduces a finite-alphabet Wiener filter precoding method for mmWave massive MU-MIMO systems that significantly reduces power consumption and hardware complexity while maintaining near-optimal performance.

Contribution

The authors propose a novel finite-alphabet Wiener filter precoding technique that approximates traditional precoding with low-precision weights, enabling low-power hardware implementation.

Findings

FAWP matrices achieve near-infinite precision performance with 3-bit weights

The approach reduces power and silicon area in mmWave massive MU-MIMO systems

Performance loss is minimal compared to traditional Wiener filter precoding

Abstract

Power consumption of multi-user (MU) precoding is a major concern in all-digital massive MU multiple-input multiple-output (MIMO) base-stations with hundreds of antenna elements operating at millimeter-wave (mmWave) frequencies. We propose to replace part of the linear Wiener filter (WF) precoding matrix by a finite-alphabet WF precoding (FAWP) matrix, which enables the use of low-precision hardware that consumes low power and area. To minimize the performance loss of our approach, we present methods that efficiently compute FAWP matrices that best mimic the WF precoder. Our results show that FAWP matrices approach infinite-precision error-rate and error-vector magnitude performance with only 3-bit precoding weights, even when operating in realistic mmWave channels. Hence, FAWP is a promising approach to substantially reduce power consumption and silicon area in all-digital mmWave massive MU-MIMO systems.