Power Domain Non-Orthogonal Transmission for Cellular Mobile Broadcasting: Basic Scheme, System Design, and Coverage Performance

Power domain non-orthogonal transmission is a promising technology for 5G wireless networks and beyond, as it can achieve higher spectrum efficiency than the orthogonal kind by multiplexing multiple users in the power domain. This article studies power domain non-orthogonal transmission for cellular mobile broadcasting to satisfy the increasing demands on multimedia communications in 5G and beyond. We first present two schemes for non-orthogonal transmission-based cellular mobile broadcasting: multi-rate and multi-service superposition transmissions, and then discuss their information-theoretical perspectives. Furthermore, we provide system designs for virtualized network architecture and physical layer processing, and discuss the key elements. We present a general superposition transmission framework to integrate three schemes developed by the 3GPP and to reduce the complexity of implementation, and then study constellation rotation to improve the BER performance of superposition transmission. Finally, we evaluate the SINR coverage performance of the presented schemes, followed by the main challenges and future research directions.