On Design Concept of Cellular Distributed MU-MIMO for Ultra-dense RAN

Abstract

In 5G and beyond 5G systems, ultra-densification of radio access network (RAN) to improve the spectrum utilization efficiency is necessary due to continuously increasing mobile data traffic volume. Simple ultra-densification of RAN is not desirable since the problems of frequent handoff and severe interference will be caused. It is desirable to build the ultra-dense RAN based on the distributed multi-user multi-input multi-output (MU-MIMO) technology. In this paper, the design concept of cellular distributed MU-MIMO is presented to realize scalable ultra-dense RAN. In cellular distributed MU-MIMO, a wide communication service area is divided into a number of disjointed areas called cells using the distributed antenna location information and then, multiple user-centric small cells called user-clusters are formed in each cell using the user location information. To effectively mitigate intra- and inter-cell interferences caused by RAN ultra-densification, fully and semi-decentralized interference coordination (IC) schemes are presented.