On the feasibility of wireless energy transfer using massive antenna arrays in Rician channels

In this paper, we examine the feasibility of wireless energy transfer (WET) using arrays with multiple antennas. Specifically, we compute the probability of outage in energy transfer over a Rician fading channel when the base station (BS) with multiple antennas transfers energy to a wireless sensor node (WSN). Through our analytical and numerical results, we prove that by deploying more antennas at the BS, the range of WET can be increased while maintaining a target outage probability. We observe that the use of massive antenna arrays at the BS results into huge savings of radiated energy. We show that for typical energy levels used in WET, the outage performance with imperfect channel state information (CSI) is essentially the same as that obtained based on perfect CSI. We also observe that a strong line-of-sight component between the BS and the WSN lowers the probability of outage in energy transfer.