On the Optimal Resource Allocation for a Wireless Energy Harvesting Node Considering the Circuitry Power Consumption

In this paper, an energy harvesting transmitter operating in a point-to-point link through a discrete-time fading channel is considered, where symbols can be transmitted through several parallel independent streams. Taking into account the different sources of energy consumption at the transmitter, the resource allocation (in terms of power allocation and selection of the active streams and channel accesses) that asymptotically maximizes the mutual information is derived by assuming that the transmitter has non-causal knowledge of the harvested energy and channel state (offline approach). The Boxed Water-Flowing graphical interpretation is presented, which intuitively depicts the asymptotically optimal offline resource allocation. Moreover, an online algorithm is proposed for the case in which the transmitter only has causal (past and present) knowledge of the harvested energy and channel state. Finally, the performance of the proposed offline and online solutions is numerically evaluated and the associated computational complexities are assessed and compared.