Cooperative transmission based on multi-relay device-to-device communications in cellular networks

In the frequency-limited cellular networks, the underlaying Device-to-Device (D2D) communications is an efficient way to enhance the user access probability and network capacity performance. To satisfy the communication requirements for users in different network sizes, a cooperative transmission strategy based on multi-relay D2D communications is proposed. Specifically, to increase the serving users simultaneously and meanwhile maintain the QoS of them, a joint admission control and cooperative nodes selection scheme is proposed, and then the power control and resource allocation scheme is provided correspondingly. Simulation results show that the proposed strategy can enhance the user access probability efficiently in frequency-limited cellular networks.