Joint subchannel and power allocation for D2D communications in cellular networks

In this paper, we consider the uplink subchannel and power allocation problem for device-to-device (D2D) and cellular links in the Orthogonal Frequency Division Multiple Access (OFDMA)-based D2D cellular network. This resource allocation problem aims to maximize the weighted sum throughput of D2D links while guaranteeing the minimum rate of each cellular link. The proposed formulation allows non-orthogonal spectrum sharing between the cellular and the D2D links to enhance the total D2D throughput. We develop an iterative algorithm that decouples the bandwidth and power allocation in two different steps and improves the objective function over iterations. For the power allocation sub-problem, we exploit the DC (difference between concave functions) structure of the objective function in the underlying problem and transform it into the convex optimization problem. We establish the convergence of the proposed algorithm. Numerical results confirm that our resource allocations algorithm outperforms other orthogonal spectrum sharing schemes.