Relay selection and resource allocation for D2D-relaying under uplink cellular power control

Device-to-Device (D2D) communication underlying 5G cellular networks enable using direct communication between devices as a relay strategy for coverage extension. We consider such a D2D-relaying approach in a scenario where there are multiple candidate devices to be selected as relays. Both backhaul and D2D transmissions are performed in uplink cellular resources, and are subject to cellular uplink power control. We investigate the relay selection and resource allocation problem for D2D-relaying in a multi-user, multi-carrier and multi-cellular network. For this purpose, we formulate a joint optimization problem and propose a simplified relay selection and resource allocation scheme. Using this scheme in a system simulation, we demonstrate that D2D-relaying under uplink power control increases the throughput of cell-edge users significantly.