Sum-Rate Optimization-based Access Mode Selection and Resource Allocation for IoT Devices in 5G

In the future fifth-generation (5G) systems, a hybrid or coexisting non-orthogonal multiple access (NOMA) and orthogonal multiple access (OMA) schemes is a promising technology that can greatly enhance network capacity and reduce interference. In this paper, we study the access mode selection and resource allocation problem for machine-type communication devices (MTCDs) in 5G. The sum-rate of the MTCDs is computed and the joint access mode selection and resource allocation problem is formulated as a sum-rate maximization problem that maximizes system sum-rate. As the original optimization problem is a nonlinear fractional problem, which cannot be solved conveniently, we transform it into power allocation subproblem and access mode selection subproblem and solve these two sub-problems successively using Lagrange dual method and heuristic algorithm. Numerical results demonstrate the effectiveness of the proposed algorithm.