Pareto-optimal power allocation of device-to-device communication with two-way decode-and-forward helping relay

This paper considers a new strategy utilizing two-way decode-and-forward (DF) relaying for device-to-device (D2D) communications underlaying cellular networks. Assuming that all the terminals have single antenna, we first derive the sum-rate expressions for both the D2D and cellular links and then propose a Pareto-optimal method to maximize the achievable sum-rate of both D2D and cellular links. Simulation results demonstrate that the sum-rate for the D2D link can be greatly enhanced without compromising the performance of the cellular link.