Interference Mitigation in D2D Communications for 5G Mobile Networks

Device to Device (D2D) application is one of most important applications that enables the wireless devices to communicate without passing their data through the core network. It reduces the complexity at the enodeB (the base station of the mobile network) and consequently enhances the overall performance of the system. The beginning of D2D application was on 4G mobile networks and nowadays, it is one of the important applications in 5G mobile networks. D2D can allocate different spectrum access such as In-band underlay, In-band overlay and Out-band. In this paper, the In-band underlay will be discussed in which the D2D users share the same frequency band allocated by the Cellular Users (CUs) to increase the spectrum efficiency. But, sharing the same frequency bands of the CUs makes the interference between the different users a big problem. In this paper, the interference will be investigated for D2D application in 5G mobile networks. Different methods will be introduced in this paper to reduce the effects of different types of interference such as the New Hybrid Frequency Reuse (NHFR) with Almost Blank Sub-frame (ABS) method, the closed mode D2D method and the combined method which is hybrid of the previous two methods. System performance using such methods will be investigated using a generic expression for Signal to Interference and Noise Ratio (SINR).