A Survey on Energy Harvesting Cognitive Radio Networks

Drastic development in the wireless communication systems is leading to the issue of spectrum scarcity and to resolve this issue, cognitive radio (CR) is emerging as one of the most capable solution. Energy harvesting phenomenon in cognitive radio networks (EH-CRNs) makes these communication systems an energy efficient one. This paper reviews the different energy harvesting techniques in CRNs, existing work on EH-CRNs and future research directions in EH-CRNs. Different energy harvesting sources for CRNs are discussed and depending upon the power storage potential of the EH-CRNs, two types of harvesting models that is harvest-use model and harvest-store-use model are explained. The existing work on EH-CRNs which includes resource allocation, throughput maximization and secure information transfer with both linear as well as non-linear energy harvesting models is discussed. Finally, future research directions in energy harvesting cognitive radios are discussed briefly.