Sustainability-Driven Resource Allocation for Energy-Harvesting Powered Device-to-Device Communication

We propose a sustainability-driven resource allocation algorithm for energy harvesting powered device-to-device (D2D) communication underlaying cellular networks. In this setup, D2D transmitters harvest energy from ambient energy sources and reuse the uplink cellular channels to perform transmission to the desired D2D receivers. Considering the time-varying and unpredictable nature of the harvested energy, the proposed algorithm ensures the energy sustainability-related quality-of-service with improved system capacity. To reach this goal, a statistical model based on the effective bandwidth/capacity is adopted to formulate the energy-harvesting/-consuming processes and evaluates the sustainability assurance in terms of the statistical outage exponent. Subsequently, we formulate the resource allocation problem with a view to maximizing the sum rate of the D2D links by jointly optimizing the power allocation and spectrum resource matching, meanwhile guaranteeing the energy sustainability requirements. By employing the Lagrangian dual method, we derive an analytical expression for the transmission power allocation and present two rules to match the cellular users with the D2D links for spectrum resource reuse. Our results reveal that both the power allocation and spectrum resource matching closely depend on the statistical outage exponent. With these theoretical analyses, we put forward a distributed subgradient-based iterative resource allocation algorithm with polynomial complexity. Finally, the simulation results demonstrate that the proposed resource allocation algorithm can acquire a substantial sum-rate improvement.