Cell-free mMIMO Support in the O-RAN Architecture: A PHY Layer Perspective for 5G and Beyond Networks

TL;DR

This paper explores the integration of cell-free massive MIMO within the O-RAN architecture, highlighting the potential for enhanced flexibility and control in 5G and future networks from a physical layer perspective.

Contribution

It provides an analysis of how cell-free MIMO can be supported in O-RAN, detailing current terminology, innovations, and identifying key research challenges.

Findings

O-RAN enables flexible resource allocation for CF networks

Cell-free MIMO can be integrated into O-RAN architecture effectively

Identifies open research challenges for future implementation

Abstract

To keep supporting next-generation requirements, the radio access infrastructure will increasingly densify. Cell-free (CF) network architectures are emerging, combining dense deployments with extreme flexibility in allocating resources to users. In parallel, the Open Radio Access Networks (O-RAN) paradigm is transforming RAN towards an open, intelligent, virtualized, and fully interoperable architecture. This paradigm brings the needed flexibility and intelligent control opportunities for CF networking. In this paper, we document the current O-RAN terminology and contrast it with some common CF processing approaches. We then discuss the main O-RAN innovations and research challenges that remain to be solved.