Beamforming for Full-Duplex Multiuser MIMO Systems

TL;DR

This paper develops joint beamforming algorithms for full-duplex multiuser MIMO systems to maximize sum rate, effectively handling interference issues through duality and iterative optimization techniques.

Contribution

It introduces novel algorithms based on uplink-downlink duality and iterative water-filling for joint beamforming in FD MU-MIMO, addressing non-convex interference challenges.

Findings

Algorithms achieve fast convergence

Low computational complexity

Effective interference management

Abstract

We solve a sum rate maximization problem of full-duplex (FD) multiuser multiple-input multiple-output (MU-MIMO) systems. Since additional self-interference (SI) in the uplink channel and co-channel interference (CCI) in the downlink channel are coupled in FD communication, the downlink and uplink multiuser beamforming vectors are required to be jointly designed. However, the joint optimization problem is non-convex and hard to solve due to the coupled effect. To properly address the coupled design issue, we reformulate the problem into an equivalent uplink channel problem, using the uplink and downlink channel duality known as MAC-BC duality. Then, using minorization maximization (MM) algorithm based on an affine approximation, we obtain a solution for the reformulated problem. In addition, without any approximation and thus performance degradation, we develop an alternating algorithm based on iterative water-filling (IWF) to solve the non-convex problem. The proposed algorithms warrant fast convergence and low computational complexity.