Orthogonal resource sharing scheme for device-to-device communication overlaying cellular networks: a cooperative relay based approach

In this paper, we propose a device-to-device (D2D) communication scheme to improve local services in cellular networks. By employing cooperative relay (CR) technology, D2D and cellular communications can operate in orthogonal resource sharing (ORS) mode with the aim of optimizing the data rates for local D2D users while fulfilling the minimum rate requirements for prioritized cellular users. In the proposed CR:based ORS scheme, we consider a cellular communication that is willing to share part of the occupied bandwidth resource with some D2D communications. Hence, the newly-obtained resource can be used by a D2D communication for the following two purposes, i.e., to compensate the rate loss of the cellular communication through cooperative relaying and to communicate its own information so as to increase its own rate. We formulated this CR-based ORS problem as a non-convex optimization problem. Hence, a global maximizer may not exist for the problem. To find the optimal solution for the problem, an effective heuristic algorithm is developed. Simulation results show that the proposed D2D communication scheme can significantly increase the rates of local D2D users and also fulfill the minimum rate requirements of cellular users.