Outage Analysis in DF Relay Assisted Two-Way Communication with RF Energy Harvesting

Energy harvesting is emerging as a promising technology enabling sustainable operation of wireless networks traditionally challenged by limited battery power. In this paper, we study bidirectional communication in a decode-and-forward (DF) relay assisted cooperative wireless network. The relay node is assumed to be capable of harvesting the energy from the received RF signals and subsequently uses it for supporting the two-way communications. For this, it follows power splitting technique used for simultaneous wireless information and power transfer. First, a closed form expression for the outage probability of the system is derived. This is followed by formulation of an unconstrained optimization problem to find out the optimal value of harvested energy for achieving minimum value of outage probability. In addition, two strategies are proposed to find out the optimal values of relay placement and harvesting time. Simulation results are used to validate the accuracy of our analytical results and illustrate the dependence of the outage probability on various system parameters, like relay placement, duration of harvesting, target rate of communication and transmit power of the users in the two-way communications.