Multi-Objective Optimization of Wireless Information and Power Transfer in Multiuser OFDMA Systems

Abstract

This paper studies joint subchannel allocation, power allocation, and beamforming for simultaneous wireless information and power transfer (SWIPT) in multiuser downlink orthogonal frequency-division multiple access (OFDMA) systems. We formulate a multi-objective optimization (MOO) problem where the objectives are to maximize both the information rate and the harvested power for all users in the system. We approach the MOO problem with two proposed methods, i.e., semidefinite relaxation-based weighted aggregation (SDR-WA) and multiobjective genetic algorithm (MOGA). Simulation compares the achievable Pareto optimal solution set yielded by these methods, and illustrates the tradeoffs of the sum information rate vs. the sum harvested power in the system.Index Terms-Energy harvesting communications, simultaneous wireless information and power transfer (SWIPT), multiobjective optimization (MOO), orthogonal frequency-division multiple access (OFDMA).

Joint Beamforming and Power Allocation for Multiuser MISO Broadcast Channel SWIPT Employing OFDM

“…Most OFDM-based SWIPT work does not consider beamforming at all [25], [26], [26]- [28], [54] or does not support multiple access [29], [30]. OFDM-based SWIPT that supports multiple users relies on subcarrier assignment for multiple access [22], [25], [54], [55], but this is redundant if using beamforming since beamforming enables multiple access through spatial multiplexing. Furthermore, subcarrier assignment is not sumrate optimal unless the network is interference limited [56], [57].…”