Robust Transceiver Design for SWIPT Multicasting MIMO Relay System with Direct Link

A robust simultaneous wireless information and power transfer (SWIPT) scheme for amplify-and-forward relay systems with a direct source-receiver link is investigated, taking into consideration imperfect channel state information (CSI). According to the minimum-mean-squared-error criterion, we formulate a joint beamforming problem under an energy harvesting constraint at the receiver plus transmitting power constraints at the source and relay. The non-convex problem is solved by semi-definite programming (SDP) and iterative method. Numerical results for mean-squared error and harvested energy performance against transmission power are evaluated. Simulation results show the improved robustness of the proposed transceiver design against the CSI errors and adjustable power splitting factor for better signal quality or more power harvesting.