Optimum Transmission Policies For Two-hop Communication With Energy Harvesting

A major limitation of wireless networks is finite battery capacity—nodes will operate for afinite duration,only as long as the battery last. Wireless systems comprised of rechargeable nodeshave a significantly prolonged lifetime and are sustainable. A distinct characteristic of these systemsis the fact that the nodes can harvest energy throughout the duration in which communication takesplace. As such, transmission policies of the nodes need to adapt to these harvested energy arrivals.Wireless systems with energy harvesting abstract more and more attention, because of the flexibledeploying, convenient maintenance and environmental friendly.First of all, the optimal transmission strategy of a single node with energy harvesting isanalyzed in the perspective of optimization problems. Further, a two-hop relaying in the presenceof energy harvesting nodes is considered. The relay network is composed of a powered source, aninfinite relay node with energy harvesting, and a destination. Simulations show that the minimumcompletion time decreases when the energy of the source increases. When the energy of sourcereaches a certain value, the minimum completion time will become to stable.In addition, a more general case is considered. The power limited of the relay node is considered.The number of the energy harvested by relay node is assumed to be2. According to deduction, anoptimal transmission strategy of minimum completion time is shown. Simulations show that themaximum amount of data that can be transmitted is limited by the energy of the node. Theminimum completion time decreases when the energy of the source increases.Finally, a compare of the transmission strategies based on two-hop relaying system is given. Inorder to deepen understanding, the differences of several transmission strategies are analyzed.