Optimum Wirelessly Powered Relaying

TL;DR

This paper optimizes the throughput of a relay-assisted wirelessly powered communication system by deriving closed-form solutions for energy beamforming and time splitting, showing improved performance over benchmarks.

Contribution

It introduces a novel optimization framework for energy beamforming and time allocation in wirelessly powered relaying systems with multiple antennas.

Findings

Optimal energy beamforming vector derived in closed form.

Optimal time split for energy harvesting and transmission obtained.

Numerical results show significant performance gains over benchmark schemes.

Abstract

This paper maximizes the achievable throughput of a relay-assisted wirelessly powered communications system, where an energy constrained source, helped by an energy constrained relay and both powered by a dedicated power beacon (PB), communicates with a destination. Considering the time splitting approach, the source and relay first harvest energy from the PB, which is equipped with multiple antennas, and then transmits information to the destination. Simple closed-form expressions are derived for the optimal PB energy beamforming vector and time split for energy harvesting and information transmission. Numerical results and simulations demonstrate the superior performance compared with some intuitive benchmark beamforming scheme. Also, it is found that placing the relay at the middle of the source-destination path is no longer optimal.