Energy Efficient Resource Allocation for Machine-to-machine Communications with NOMA and Energy Harvesting

The vast amount of the machine type communication devices (MTCDs) in machine-to-machine (M2M) communications and their limited energy budget are the crucial challenges to transmission scheme design. This paper proposes an energy-efficient power control and time scheduling scheme in M2M communications with non-orthogonal multiple access (NOMA) and energy harvesting. User equipment (UEs) are configured as gateways for MTCDs. Our aim is to minimize the total energy consumption of both MTCDs and UEs, on condition that the throughput constraints for both MTCDs and UEs as well as the minimal required harvested energy constraints for MTCDs are satisfied. We obtain the optimal conditions for the total energy minimization problem. Numerical results show that the proposed algorithm achieves the optimal energy consumption.