Date Added: Nov 2012
Far-field wireless recharging based on Microwave Power Transfer (MPT) will free mobile devices from interruption due to finite battery lives. Integrating MPT with wireless communications to support Simultaneous Information-and-Power Transfer (SIPT) allows the same spectrum to be used for dual purposes without compromising the quality of service. In this paper, the authors propose the novel approach of realizing SIPT in a broadband downlink system where users are assigned orthogonal frequency sub-channels and a base station transfer's information and energy to users over spatially separated channels called the data and MPT channels. Optimizing the power control for such a system results in a new class of multiuser power-control problems featuring the circuit-power constraints, namely that the wirelessly transferred power must be sufficiently large for operating receiver circuits.