Resource allocation for maximizing the device-to-device communications underlaying LTE-Advanced networks

Device-to-device (D2D) communications as an underlaying LTE-Advanced network has proven to be efficient in improving the network performance and releasing the traffic load of eNodeB. By sharing radio resource with cellular user equipments (CUEs), D2D communications can significantly enhance the overall spectral efficiency. However, the resulting mutual interference may cancel or even outweigh the gain brought by D2D communications. In this paper, we avoid the interference through a well designed resource allocation scheme. We formulate the uplink resource allocation problem where more than one D2D pair can share the same resource with one CUE under the constraint that the SINR requirements of CUEs and admitted D2D pairs are satisfied. The optimization resource allocation is shown to be NP-hard, and an interference degree based Greedy heuristic Resource Allocation algorithm (GRA) is explored to maximize the number of admitted D2D pairs by properly selecting a group of D2D pairs for each CUE. Simulation results show the efficacy of the proposed algorithm.