Efficient Resource Allocation for Overlay D2D Communication: A Comprehensive Review

Device-to-device communication is the most crucial aspect of the fifth generation (5G) wireless networks. D2D communication is a technology that allows User Equipment (UE) to communicate with each other with or without the involvement of any base stations or any network infrastructures. In the overlay, there are dedicated resources for both cellular and D2D users thus there is no interference between them. Therefore, the in-band resources for D2D communication can be operated in overlay mode. But there is a wastage of resources in overlay D2D communication because the resources are dedicated to both cellular and D2D users. This paper gives critical review of previously published resource allocation algorithms of overlay D2D communication in terms of spectral efficiency, resource optimizations, outage probability, transmission capacity and power efficiency. The main contribution of this paper is to summarize the published work and future challenges in the field of overlay D2D communication that is linked with 5G.