Using Non-Orthogonal Multiplexing for In-Band Full-Duplex Backhaul for 5G Broadcasting

Abstract

Delivering broadcast-type services is one of the main use cases defined for the next generation 5G system. To deliver robust mobile broadcast services, single-frequency-network (SFN) is preferred due to the inherent spatial diversity. However, each SFN transmitter requires a backhaul link, which results in high infrastructure cost, especially for small cell networks with large number of transmitters. This paper proposes a cost-efficient in-band full-duplex backhaul solution using power-based non-orthogonal multiplexing technology (P-NOM). In the proposed solution, the backhaul data and mobile services are transmitted in different signal layers in a P-NOM system at the same time and using the same spectrum. In order to achieve SFN operation, careful timing control on the backhaul and service transmissions is designed. When comparing to in-band backhaul solutions using orthogonal multiplexing (OM) technologies, the proposed P-NOM based technology achieves higher spectrum efficiency and network scalability. In addition, the proposed technology can be directly applied for backhaul transmission in mixed unicast and broadcast delivery, which is a desired feature for 5G to achieve more efficient use of spectrum.