Joint Beamforming and Power Splitting for Wideband Millimeter Wave SWIPT Systems

Simultaneous wireless information and power transfer (SWIPT) is a promising technology for enabling future internet-of-things applications particularly with battery-limited devices including autonomous vehicles, mobile robots, and distributed sensors. In recent years, there has been a growing interest in millimeter wave (mmWave) SWIPT because a wider energy coverage is provided by mmWave power transfer using a large antenna array than lower frequency solutions. However, research on mmWave SWIPT systems is lacking especially with practical hardware in spite of its importance. In particular, transmitter, information receivers, and nonlinear energy harvesters should be jointly designed under the constraints of transmit power and analog-digital hybrid beamforming structure. In this paper, we develop a joint design of transmit power allocation, beamforming, and receive power splitting for SWIPT downlink systems in wideband mmWave channel. The proposed scheme relies on the limited feedback of channel information. Also, the rate-energy region of the proposed mmWave SWIPT system is analyzed and the performance is verified by simulations.