Distance-based resource allocation scheme for device-to-device communications underlaying cellular networks

Recently, there has been growing interest in device-to-device (D2D) communications in a cellular network such as LTE-advanced. However, enabling D2D links in a cellular network presents a challenge in radio resource management due to the interference between cellular and D2D links. Some studies have considered cellular users as the primary and proposed methods to protect them from the additional interference from D2D links. However, considering that the D2D function is suitable for short-range and high-rate links, and local multimedia services, it is also important to guarantee these D2D links reliable. Thus, in this paper, we propose a method to properly choose a cellular user that shares radio resource with D2D users in the uplink to mitigate the interference from the cellular user to the D2D receivers. Numerical results show that by applying our method the reliability of D2D communication improves significantly without degrading the performance of the cellular connection. In addition, we derive a closed-form expression for the conditional outage probabilities of D2D links in the case when more than one D2D pair share the same resource with one cellular user, and discuss how the base station can choose a cellular user to optimize the performance of the D2D links.