The advent of device-to-device (D2D) communication technology is fast receiving attention among researchers for the past decade. In a cellular network, D2D is considered as direct communication between mobile users within network proximity without traversing base station (BS) . D2D communication has unique advantages compared to existing communication techniques. D2D communication is believed to be able to significantly enhance cellular networks in terms of system capacity, area coverage, peak rates, throughput, latency, user experience, etc. Furthermore, considering the short communication range between D2D users, D2D communication is envisioned to improve energy efficiency, delay, spectrum efficiency, as well as improve the cellular loads traffic .
However, the D2D communication technology poses significant challenges, which includes, signaling of D2D communications, problem of interference between D2D communication mode and cellular mode, and the allocation of resource of D2D communications .
For interference to be properly managed in a D2D communication there is need to solve the issue of poor link quality of D2D connections. This paper analysis the performance of Relay Aided Underlaying technique in IoT-D2D communication which will serve as a model to improve D2D communications with the IoT systems with no extra construction and maintenance cost.