[Paper Review] An Enhanced Leakage-Based Precoding Scheme for Multi-User Multi-Layer MIMO Systems

Chun-Liang Yang|arXiv (Cornell University)|Jul 15, 2014

Advanced MIMO Systems Optimization6 references3 citations

TL;DR

This paper proposes an enhanced leakage-based precoding scheme, termed layer signal-to-leakage-plus-noise ratio (layer SLNR), for multi-user multi-layer MIMO systems. By integrating the MIMO receiver structure into precoder design and accounting for both inter-user and intra-user inter-layer interference, the scheme improves signal-to-interference balance, resulting in superior system performance over conventional methods.

ABSTRACT

In this paper, we propose an enhanced leakage-based precoding scheme, i.e., layer signal to leakage plus noise ratio (layer SLNR) scheme, for multi-user multi-layer MIMO systems. Specifically, the layer SLNR scheme incorporates the MIMO receiver structure into the precoder design procedure, which makes the formulation of signal power and interference / leakage power more accurate. Besides, the layer SLNR scheme not only takes into account the inter-layer interference from different users, but also takes care of the inter-layer interference from the same user which is usually assumed to be zero in previous studies. As a result, the proposed layer SLNR scheme produces a good balance between the layer signal power and layer interference power in a multi-user multi-layer MIMO system, therefore achieves better system performance. The effectiveness and superiority of the proposed layer SLNR scheme are validated via simulations.

Motivation & Objective

• To address the limitation of existing leakage-based precoding schemes that neglect intra-user inter-layer interference.
• To improve system performance in multi-user multi-layer MIMO by refining signal and interference power modeling.
• To develop a precoding scheme that balances layer signal power and interference power more accurately through receiver-aware design.
• To validate the superiority of the proposed scheme via simulation under realistic multi-layer MIMO conditions.

Proposed method

• The layer SLNR scheme incorporates the MIMO receiver structure into the precoder design process to improve accuracy in modeling signal and interference power.
• It formulates signal power and interference/leakage power based on the actual receiver configuration, enhancing precision compared to conventional approaches.
• The scheme explicitly models both inter-user and intra-user inter-layer interference, which are often ignored or assumed zero in prior work.
• The precoder is optimized to maximize the layer signal-to-leakage-plus-noise ratio (layer SLNR), balancing desired signal power and interference power.
• The optimization is performed under power constraints to ensure practical feasibility.
• The resulting precoder is designed to enhance spectral efficiency and robustness in multi-user multi-layer MIMO systems.

Experimental results

Research questions

• RQ1 How does accounting for intra-user inter-layer interference affect precoding performance in multi-user multi-layer MIMO systems?
• RQ2 Can integrating the MIMO receiver structure into precoder design lead to more accurate modeling of signal and interference power?
• RQ3 What performance gains are achievable by optimizing the layer SLNR compared to conventional leakage-based precoding?
• RQ4 How does the proposed scheme compare to existing precoding methods in terms of spectral efficiency and interference suppression?
• RQ5 Does the layer SLNR scheme maintain robustness under realistic multi-layer MIMO channel conditions?

Key findings

• The proposed layer SLNR scheme achieves better system performance than conventional leakage-based precoding by explicitly modeling both inter-user and intra-user inter-layer interference.
• Incorporating the receiver structure into the precoder design leads to a more accurate formulation of signal and interference power, improving overall system efficiency.
• The scheme demonstrates improved balance between desired signal power and interference power, resulting in enhanced spectral efficiency.
• Simulations confirm the superiority of the layer SLNR scheme in terms of sum rate and error rate performance.
• The method outperforms existing approaches, particularly in scenarios with high inter-layer interference, due to its comprehensive interference modeling.