Wireless-Powered Two-Way Relaying with Power Splitting-based Energy Accumulation

TL;DR

This paper proposes a novel power splitting-based energy accumulation scheme for wireless-powered two-way relay networks, enabling the relay to harvest and store energy before forwarding information, thus improving throughput over existing methods.

Contribution

It introduces a new PS-EA scheme with a finite-state Markov Chain model for energy accumulation, enhancing system throughput in wireless-powered relay networks.

Findings

The PS-EA scheme outperforms TS-EA and non-accumulation schemes.

Closed-form throughput expressions are derived for Nakagami-m fading channels.

Numerical results confirm the effectiveness of the proposed scheme.

Abstract

This paper investigates a wireless-powered two-way relay network (WP-TWRN), in which two sources exchange information with the aid of one amplify-and-forward (AF) relay. Contrary to the conventional two-way relay networks, we consider the scenario that the AF relay has no embedded energy supply, and it is equipped with an energy harvesting unit and rechargeable battery. As such, it can accumulate the energy harvested from both sources' signals before helping forwarding their information. In this paper, we develop a power splitting-based energy accumulation (PS-EA) scheme for the considered WP-TWRN. To determine whether the relay has accumulated sufficient energy, we set a predefined energy threshold for the relay. When the accumulated energy reaches the threshold, relay splits the received signal power into two parts, one for energy harvesting and the other for information forwarding. If the stored energy at the relay is below the threshold, all the received signal power will be accumulated at the relay's battery. By modeling the finite-capacity battery of relay as a finite-state Markov Chain (MC), we derive a closed-form expression for the system throughput of the proposed PS-EA scheme over Nakagami-m fading channels. Numerical results validate our theoretical analysis and show that the proposed PS-EA scheme outperforms the conventional time switching-based energy accumulation (TS-EA) scheme and the existing power splitting schemes without energy accumulation.