Power optimization of D2D communications underlying cellular networks in multi-user scenario

In this paper, power allocation problem is presented for device-to-device (D2D) communications underlying cellular networks in multi-user scenario. In this scenario, multiple D2D pairs are allowed to share one cellular resource. As a preliminary study, we consider the scenario with only two D2D pairs and propose a power optimization scheme under this scenario. For cellular link and the D2D links sharing the same channel resource, the proposed scheme calculates the transmit power for each of them by iterative algorithm. The results show that the proposed scheme can achieve the optimal system capacity on the premise of ensuring the cellular communication quality.