Markov Chain Based Outage Analysis of Wireless Powered Relay Networks

This paper studies the outage performance of wireless powered relay networks using the Markov chain theory. By adopting the discrete-level model to the finite-capacity energy storage, the energy arrival and departure of the wireless powered relay is characterized, based on which the state transitions among all the energy states are formulated. The theoretical expressions of three kinds of outage probabilities, namely the connection outage probability (COP), the energy outage probability (EOP) and the overall outage probability (OOP) of the proposed network are derived. It has been found that the EOP would be significantly decreased by increasing the transmit power of source, the energy conversion efficiency, a ndbyr educing the distance of source-relay link, while the COP would decline severely by reducing the transmission rate and the distance of relay-destination link. The results also demonstrate that the OOP would be dominated by COP with short distance of source-relay link and long distance of relay-destination link. By contrast, when the distances of source-relay and relay-destination links get longer and shorter, respectively, the EOP would become dominant to the OOP. Numerical simulations have illustrated the validity of the theoretical analysis.