Joint optimal beamforming and power control in cell-free massive MIMO

TL;DR

This paper presents a fast, optimal algorithm for joint power control and beamforming in cell-free massive MIMO networks, addressing practical issues like imperfect cooperation and limited channel information sharing.

Contribution

It introduces the first joint optimization framework for long-term power control and distributed beamforming in cell-free massive MIMO with imperfect cooperation.

Findings

Algorithm achieves optimal solutions efficiently.

Proposed variation converges faster in practice.

Addresses practical limitations like limited channel info sharing.

Abstract

We derive a fast and optimal algorithm for solving practical weighted max-min SINR problems in cell-free massive MIMO networks. For the first time, the optimization problem jointly covers long-term power control and distributed beamforming design under imperfect cooperation. In particular, we consider user-centric clusters of access points cooperating on the basis of possibly limited channel state information sharing. Our optimal algorithm merges powerful power control tools based on interference calculus with the recently developed team theoretic framework for distributed beamforming design. In addition, we propose a variation that shows faster convergence in practice.