Rate-Energy Region of Joint Information and Energy Transfer in a Two-User MIMO Interference Channel

This letter considers joint information and energy transfer in a two-user MIMO interference channel in which one receiver decodes information and the other harvests energy. We prove the energy beamforming is optimal for the energy transmitter irrespective of the operating SNR. We maximize the weighted sum of rate and energy to characterize the region of rate-energy pairs that are achievable using Gaussian signaling. We propose a numerical algorithm based on the alternating optimization technique because the maximization problem is a non-convex problem. The proposed algorithm converges to a KKT point of the maximization problem. Numerical results show that the rate-energy region of the algorithm is larger than those of the existing suboptimal algorithms. In addition, the algorithm harvests 60% more energy in the high-information transfer region than the suboptimal algorithms.