Energy efficient resource allocation for wireless power transfer enabled massive MIMO system

This paper proposes an energy-ef&cient resource allocation scheme for a wireless power transfer (WPT) enabled multi-user massive MIMO system with imperfect channel estimation. In the considered system, the users who have data to be transmitted only can be empowered by the WPT in the downlink from a base station (BS) with a large scale of multiple antennas. The problem of optimizing the energy ef&ciency objective is formulated with consideration of beamforming design, antenna selection, power allocation and time division protocol based on the practical consideration, i.e., imperfect channel state information (CSI) at the BS. In particular, the proposed antenna selection scheme is to &nd the optimal number of antennas and then employ the energy beamforming. The nonlinear fractional programming based scheme is utilized to address optimization of energy ef&ciency and to &nd the optimal power and time allocation. Performance evaluation is presented to demonstrate the effectiveness of the proposed schemes.