Tutorial on Rate-Splitting (Multiple Access) for 6G

This tutorial argues that to efficiently cope with the high throughput, reliability, heterogeneity of Quality-of-Service (QoS), and massive connectivity requirements of future multi-antenna wireless networks, multiple access and multiuser communication system design need to depart from the two extreme interference management strategies, namely fully treat interference as noise (as commonly used in 5G, MU-MIMO, CoMP, Massive MIMO, millimetre wave MIMO) and fully decode interference (as in NOMA). In this tutorial, we depart from those two extremes and introduce the audience to a general and powerful transmission framework based on Rate-Splitting (RS). RS relies on the split of messages and the non-orthogonal transmission of common messages decoded by multiple users, and private messages decoded by their corresponding users. This enables RS to partially decode interference and partially treat the remaining interference as noise, and therefore softly bridge and reconcile the two extreme strategies of fully decode interference and treat interference as noise. As a result, RS provides a unified and flexible framework for the design and optimization of non-orthogonal transmission, multiple access, and interference management strategies. This tutorial is dedicated to the theory, design, optimization and applications of RS and demonstrates the significant benefits in terms of spectral/energy efficiencies, reliability and robustness to Channel State Information imperfections over conventional strategies used in 5G (multi-user MIMO, massive MIMO, CoMP, mmwave MIMO) and NOMA, in a wide range of deployments, network loads (underloaded, overloaded), services (unicast, multicast) and systems (terrestrial and satellite). The tutorial gives the audience a comprehensive introduction of the state-of-the-art development in rate splitting theory and applications in wireless systems. More info (including presentation material): https://sites.google.com/view/ieee-comsoc-wtc-sig-rsma/home Matlab codes available for download at the bottom of http://www.ee.ic.ac.uk/bruno.clerckx/Research.html