Exploiting spatial reuse gain through joint mode selection and resource allocation for underlay device-to-device communications

Device-to-device (D2D) communication has recently emerged as a promising technique for improving the performance of next-generation cellular systems. In particular, traffic offloading through exploiting spatial reuse gain of underlay D2D communication has gained attention in the literature. While related work has considered the scenario where at most one underlay D2D pair can share the radio resource of cellular users, we consider in this paper a more general scenario involving multiple D2D pairs for resource sharing. To investigate the resultant performance gain, we first formulate a joint optimization problem for mode selection and resource allocation, where the optimal mode to operate, radio resources to use, and power to transmit are to be optimally decided for a group of users with intra-cell traffic. The formulated problem belongs to MINLP, and hence we propose an algorithm with reduced complexity for solving the problem. Evaluation results show that, through joint mode selection and resource allocation among multiple D2D pairs, the potential of D2D communications can be further exploited for achieving significant performance gain.