Energy efficient resource allocation for D2D multicast communications

The resource allocation for device-to-device (D2D) multicast communications is investigated. To achieve fair energy efficiency (EE) among different multicast groups, the max-min fairness criterion is used as the optimization criterion and the EE of D2D multicast groups are taken as the optimization objective function. The aim is to maximize the minimum EE for different D2D multicast groups under the constraints of the maximum transmit power and minimum transmit rate, which is modeled as a non-convex and mixed-integer fractional programming problem. Here, suboptimal resource allocation algorithms are proposed to solve this problem. First, channel assignment scheme is performed to assign channel to D2D multicast groups. Second, for a given channel assignment, iterative power allocation schemes with and without loss of cellular users' rate are completed, respectively. Simulation results corroborate the convergence performance of the proposed algorithms. In addition, compared with the traditional throughput maximization algorithm, the proposed algorithms can improve the energy efficiency of the system and the fairness achieved among different multicast groups.