Optimization and Cognitive Radio-Assisted Access Control Scheme for D2D Communication

Device-to-Device (D2D) communication has emerged as a promising technology to enhance the spectral efficiency and capacity of wireless networks. However, severe interference and large-scale fading hinder the performance of resource allocation. Toward this issue, various improvements have been made in D2D resource allocation using game theory, graph theory, and optimization techniques. But it lacks in offering physical layer access control, due to which the aforementioned improvements are computationally expensive. In this paper, we aim to first find the CUs whose resources are free and then allocate them to the best D2D users by considering the channel conditions between the CU-D2D pair. This is a multi-integer nonlinear programming problem that comprises of a multiobjective function, i.e., find the CUs and allocate their resource to the best D2D user. For that, a whale optimization algorithm (WOA) is proposed. It first locates the CUs (resource free) from the cognitive radio (CR) network and then forwards them to the resource allocation process. At each iteration of WOA, the whales find the optimal CU-D2D pair based on their channel conditions (signal-to-interference-plus-noise ration (SINR)) for efficient resource a llocation. W OA acts as an access control mechanism that finds optimal CUs and D2D users to participate in resource allocation, discarding other pairs. The proposed scheme is evaluated by considering evaluation metrics, such as false detection probability (85.6 %), selection of optimal CU-D2D pair using WOA, and system throughput (19.1 Mbps).