QoS-based multicast beamforming for SWIPT

This paper considers simultaneous wireless information and power transfer (SWIPT) in multiple-input multiple-output (MIMO) multicasting systems where each receiver is equipped with power splitting devices and can receive both information and energy from the base station (BS) continuously at the same time. We investigate the joint multicast transmit beamforming and receive power splitting problem for minimizing the transmit power of the BS subject to signal-to-noise ratio (SNR) and energy harvesting constraints at each receiver. Both scenarios of perfect and imperfect channel state information (CSI) at the BS are studied. For the imperfect CSI case, we consider worst-case based design. Due to non-convexity of the problems, we use semidefinite relaxation (SDR) technique to solve the problems. Interestingly, we show that the SDR is in fact tight in certain scenarios. Numerical simulations are performed to demonstrate the effectiveness of the proposed algorithms.