Using Non-Orthogonal Multiplexing for Enhancing Unicast-Broadcast Transmission Capacity in 5G

3GPP is working on a 5G multimedia broadcast multicast service (5G-MBMS) subsystem to deliver broadcast-type services and to achieve higher spectrum utilization for applications that can benefit from using point-to-multipoint (PTM) transmissions. The 5G-MBMS subsystem should provide a unified transmission platform for delivering mixed unicast, multicast, and broadcast services, with adaptive resource allocation and high spectrum efficiency. Up to the latest PTM system in the 3GPP Long Term Evolution (LTE), orthogonal multiplexing (OM) methods are used to combine the different types of services in one channel. This paper studies the capacity benefits of using power-based non-orthogonal multiplexing (P-NOM) technology in 5G-MBMS. For LTE/5G systems delivering mixed broadcast and unicast services, using P-NOM offers a solution to significantly increase the cell capacity for unicast services, while providing broadcast services with required quality of service. It is further shown that using P-NOM to combine broadcast and unicast services does not require new radio resource scheduling algorithms, i.e., existing scheduling algorithms for unicast-only networks can be used.