Resource Allocation and Admission Control for an Energy Harvesting Cooperative OFDMA Network

This paper addresses the problem of joint resource allocation and admission control for an energy harvesting (EH)-based cooperative orthogonal frequency-division multiple access network, where multiple source-destination pairs and an EH amplify-and-forward relay coexist. Specifically, the relay first employs the power splitting technique to scavenge energy from radio frequency signals emitted by source nodes and then leverages the harvested energy to forward data for source nodes when necessary. Under imperfect channel state information, we first design a distributed robust resource allocation scheme to efficiently allocate system subcarriers, and the relay's and source nodes' transmit powers together with selecting the suitable power splitting ratios for the relay. Then, for the admission control, which is important but has hardly been studied for EH networks, we propose a fuzzy-logic-based admission control policy to determine the network access of each source-destination pair, if not all source-destination pairs' quality-of-service (QoS) requirements can be satisfied. In particular, considering the EH nature of the relay, this policy not only considers the QoS and the priority of each source-destination pair, but also takes account of the contribution of each source-destination pair to the relay's energy harvesting, and the energy efficiency to utilize the relay's energy. Finally, we evaluate and verify the performance of the proposed resource allocation and admission control schemes through numerical experiments.