A Unified Optimization Framework for Multicarrier MIMO SWIPT Systems

This paper proposes a unified optimization framework for a power splitting (PS)-based multicarrier multiple-input and multiple-output (MIMO) simultaneous wireless information and power transfer (SWIPT) system with Tomlinson-Harashima pre coding (THP)-based non-linear transceivers or linear transceivers. Our aim is to minimize the transmit power under the sum mean-square-error (MSE) and energy harvesting (EH) constraints. To solve this formulated non-convex problem, we propose a structural solution (SS) which applies the closed-form expressions of equalization matrices, feedback matrices and precoding matrices to establish an equivalent optimization problem in terms of the power allocation and PS ratio. Then the equivalent problem is solved by a two-layer optimization scheme. Simulation results show that the THP-based non-linear transceivers need less transmit power than linear transceivers to achieve the same performance of EH and sum MSE.