Resource allocation in D2D communication in cellular mode

Device-to-Device (D2D) has attracted substantial research attention recently and has been recognized as an essential approach to performance improvement in 5G networks, due to its potential to improve coverage, spectrum efficiency, and energy within the existing cellular network. In this paper, we refer to an LTE-A scenario in which the underlay mode is adopted to allow D2D pairs to communicate directly by sharing sub-channels with Cellular Users (CUEs) and cellular mode (CELLM), where two D2D users communicate through the eNB as conventional CUEs and no direct D2D link is established. In this case, the eNB is used as a relay. Our aim is to propose heuristic resource allocation schemes to distribute radio resources among CUEs and D2Ds in a cell taking the interference because of pairing into account. Finally, an analytical approach is proposed to characterize CUE and D2D capacity as well as outage probability for D2D cellular mode.  This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.