Optimal resource management for device-to-device communications underlaying SC-FDMA systems

In this paper we propose an optimal resource management scheme for device-to-device (D2D) communications utilising uplink resources in a Single Carrier Frequency Division Multiple Access (SC-FDMA) system, which is the uplink access scheme in the 3GPP-Long Term Evolution (LTE) standard. We consider an arbitrary number of conventional cellular (CC) User Equipments (UEs) and D2D UEs, both utilising the same uplink resources. We leverage a practical capacity formula that takes into account the saturation effects of practical modulation schemes to optimise the power control for both CC and D2D UEs subject to certain Quality-of-Service (QoS) constraints. We then formulate the resource block (RB) allocation problem as a job sequence problem and apply the dynamic programming algorithm to solve the problem. Finally, we combine these two aspects together and propose a composite resource management scheme for D2D communications. Simulation results show that by our proposed scheme, a substantial improvement in the total throughput of D2D communications can be achieved while maintaining the QoS requirements of CC UEs.