Power Optimization in Multimedia Sharing in Device to Device Communication Underlaying Cellular Networks

In this paper, we study a device to device (D2D) communications underlaying cellular network where D2D pairs can reuse a cellular user (CU) resource block (RB) simultaneously, to share multimedia files. It is well known that the delay plays an important role in real-time services. Here, to ensure the fairness between D2D pairs while satisfying the quality of service (QoS) requirements, we maximize the minimum utility function of D2D users under delay and interference restrictions. The sigmoid function is used as the utility function in the optimization problem. We show that this optimization problem is NP-hard and thus, we introduce an effective iterative method to solve it. Simulation results reveal significant improvement in comparison to other power allocation schemes and demonstrate that the proposed scheme can effectively guarantee the fairness between D2D pairs under QoS conditions of CU and D2D pairs. Moreover, simulation results also indicate that the convergence rate of our proposed algorithm is quite fast.