Energy diversity and opportunistic energy harvesting based cooperative communication with SWIET under RF interference

Wireless powered relaying is a promising cooperative communication technique which has drawn much attention recently. In this paper, we investigate a cooperative communication system where a source node (SN) communicates with a destination node (DN) with the help of an energy-constrained relay node (RN) in the presence of interference. We consider a general scenario where a direct link between SN and DN is available, though the quality may be poor due the long distance or obstacles between the two nodes. Based on the concepts of energy diversity (ED) and opportunistic energy harvesting (OEH), we first provide a new ED-OEH protocol, which allows RN harvests energy or processes information on a time-frame basis. Then, under the ED-OEH protocol, we propose a novel wireless power and information transfer algorithm for the cooperative communication system, which can adaptively switch the relay operation mode according to the amount of harvested energy, the interference power and the quality of the system links to efficiently utilize the ED of the direct link and achieve OEH in the investigated system to improve the system throughput. To verify the performance of our proposed algorithm, we conduct comprehensive computer simulations with various system settings. Simulation results show that our proposed scheme achieves significant throughput gains over the existing schemes in literature.