Study of Robust Power Allocation for User-Centric Cell-Free Massive MIMO Networks

TL;DR

This paper introduces a robust power allocation method for user-centric cell-free massive MIMO networks that effectively handles channel uncertainties, improving reliability and efficiency in large-scale wireless systems.

Contribution

It proposes a novel least-squares based power optimization with Tikhonov regularization integrated with zero-forcing precoding for robustness against CSI errors.

Findings

Outperforms existing non-robust power allocation techniques.

Maintains low computational complexity suitable for large-scale networks.

Enhances system reliability under channel estimation uncertainties.

Abstract

In cell-free massive multiple-input multiple-output (MIMO) networks, robust resource allocation is critical to ensure reliable system performance in the presence of channel uncertainties resulting from imperfect channel state information (CSI). In this work, we propose a robust power allocation method that formulates the power optimization problem into a least-squares framework, enhanced by Tikhonov regularization to mitigate the adverse effects of channel estimation errors. We integrate our approach with zero-forcing precoding, enabling a design that is both computationally efficient and resilient to CSI imperfections. Numerical results indicate that the proposed method outperforms existing non-robust techniques while benefiting from low computational overhead, making it well-suited for large-scale deployments under CSI uncertainty.