Robust Precoding for Resilient Cell-Free Networks

TL;DR

This paper introduces a robust precoding method for cell-free massive MIMO systems that accounts for channel estimation errors, improving resilience and performance while maintaining computational efficiency.

Contribution

It proposes a novel robust precoder design that incorporates CSI error statistics and an efficient alternating optimization algorithm for resilient CF-mMIMO systems.

Findings

Significantly outperforms conventional linear precoders.

Provides a good balance between performance and computational complexity.

Ensures fast convergence of the optimization algorithm.

Abstract

This paper presents a robust precoder design for resilient cell-free massive MIMO (CF-mMIMO) systems that minimizes the weighted sum of desired signal mean square error (MSE) and residual interference leakage power under a total transmit power constraint. The proposed robust precoder incorporates channel state information (CSI) error statistics to enhance resilience against CSI imperfections. We employ an alternating optimization algorithm initialized with a minimum MSE-type solution, which iteratively refines the precoder while maintaining low computational complexity and ensuring fast convergence. Numerical results show that the proposed method significantly outperforms conventional linear precoders, providing an effective balance between performance and computational efficiency.