A Unified Linear Precoding Design for Multi-user MIMO Systems

TL;DR

This paper proposes a unified linear precoding matrix for multi-user MIMO systems that combines sub-optimal and optimal precoders to eliminate the BER performance gap across all SNR regimes.

Contribution

A novel unified linear precoding technique that adaptively combines sub-optimal and optimal precoders to achieve consistent BER performance.

Findings

Significant BER performance improvement across SNR regimes.

Elimination of the BER gap between sub-optimal and optimal precoders.

Enhanced robustness of MIMO broadcast systems.

Abstract

We address the problem of the bit error rate (BER) performance gap between the sub-optimal and optimal linear precoder (LP) for a multiuser (MU) multiple input and multiple output (MIMO) broadcast systems in this paper. Particularly, mobile users suffer noise enhancement effect due to a sub-optimal LP that can be suppressed by an optimal LP matrix. A sub-optimal LP matrix such as a linear zero-forcing (LZF) precoder performs in high signal to noise ratio (SNR) regime only, in contrast, an optimal precoder for instance a linear minimum mean-square-error (LMMSE) precoder outperforms in both low and high SNR scenarios. These kinds of precoder illustrates the BER gap distance at least 0.1 when it is used in itself in a MU MIMO systems. Thus, we propose and design a unified linear precoding (ULP) matrix using a precoding selection technique that combines the sub-optimal and optimal LP matrix for a multi-user MIMO systems to ensure zero BER performance gap in this paper. The numerical results show that our proposed ULP technique offers significant performance in both low and high SNR scenarios.