Joint multi-objective transmit precoding and receiver time switching design for MISO SWIPT systems

In this paper, we consider a time-switching (TS) co-located simultaneous wireless information and power transfer (SWIPT) system consisting of multiple multi-antenna access points which serve multiple single antenna users. In this scenario, we design jointly the optimal transmit precoding covariance matrix and the TS ratio for each receiver to maximize the utility vector made of the achieved data rates and the energy harvested of all users simultaneously. This is a non-convex multi-objective optimization problem which has been transformed into an equivalent non-convex semidefinite programming and solved using local optimization method of sequential convex programming. Numerical results illustrate the trade-off between energy harvested and information data rate objectives and show the effect of optimizing the precoding strategy and TS ratio on this trade-off.