Performance for device-to-device communication with three-time-slot two-way amplify-and-forward relay protocol

Multi-hop device-to-device (D2D) communication can significantly improve the system performance. This paper studied the outage performance of D2D communication assisted by another D2D user using three-timeslot two-way amplify-and-forward relaying protocol over Rayleigh fading channels. Considering the co-channel interference from cellular user at the D2D node, the approximate expression for the overall outage probability was derived. Furthermore, a power allocation optimum method to minimize the outage probability was developed, and the closed form expression for the optimal power allocation coefficient at the relay was derived. Simulation results demonstrate accuracy of the derived outage probability expressions. Simulation results also demonstrate that the outage performance can be improved using the proposed optimal power allocation method.