Wireless Power Transfer in Two-Way AF Relaying with Maximal-Ratio Combining under Nakagami-m Fading

Abstract

In this paper, we analyze the performance of simultaneous wireless information and power transfer (SWIPT) in two-way relay systems with an active direct link under Nakagami-m fading environment. We consider a three-node based cooperative relaying system consisting of two source nodes and a battery-enabled relay node. Herein, one round of information exchange between source nodes can be accomplished in three time phases. Relay node relies on amplify-and-forward (AF) operation to broadcast the signals, while the destination nodes utilize maximal-ratio combining (MRC) technique to make use of both the direct and relay links. Moreover, the relay node harvests energy from the radio-frequency (RF) signals in the first two phases using power-splitting (PS) approach and then utilizes the harvested energy for information processing and broadcasting the received signals in the third phase. For the considered setup, we proficiently derive accurate expressions for the outage probability (OP), system throughput, and energy efficiency. Numerical results enlighten the importance of considering direct link with MRC in the SWIPT-enabled two-way relay systems.