A New SLNR-based Linear Precoding for Downlink Multi-User Multi-Stream MIMO Systems

TL;DR

This paper introduces a new SLNR-based linear precoding method for downlink multi-user MIMO systems that improves error performance in multi-stream transmission with minimal impact on sum-rate.

Contribution

It proposes a novel precoding scheme using simultaneous diagonalization, relaxing SLNR maximization to enhance per-stream channel gain uniformity.

Findings

Significant error performance improvement over original SLNR precoding.

Maintains nearly the same sum-rate as existing methods.

Reduces the gap between per-stream effective channel gains.

Abstract

Signal-to-leakage-and-noise ratio (SLNR) is a promising criterion for linear precoder design in multi-user (MU) multiple-input multiple-output (MIMO) systems. It decouples the precoder design problem and makes closed-form solution available. In this letter, we present a new linear precoding scheme by slightly relaxing the SLNR maximization for MU-MIMO systems with multiple data streams per user. The precoding matrices are obtained by a general form of simultaneous diagonalization of two Hermitian matrices. The new scheme reduces the gap between the per-stream effective channel gains, an inherent limitation in the original SLNR precoding scheme. Simulation results demonstrate that the proposed precoding achieves considerable gains in error performance over the original one for multi-stream transmission while maintaining almost the same achievable sum-rate.