Optimal Resource Allocation for Device-to-Device Communication Underlying 5G Cellular Downlink Network

Device-to-Device (D2D) communication is a promising technology for upcoming fifth-generation cellular communication. Since in D2D communication, devices can transmit data between each other without any assistance from the base station, it will gradually increase the network throughput and reduce the power consumption, which makes D2D communication a key candidate for the upcoming 5G cellular network. D2D communication underlays within the existing cellular network makes it more complex. One of the fundamental challenges is to allocate the resources to the D2D communication. In this paper, we proposed an optimal resource allocation strategy for D2D communication underlying 5G cellular network for the downlink ransmission. We considered a single cell scenario consisting of one single base station and multiple cellular users and multiple D2D pairs. All the resources will be allocated to the cellular users (CUs) as they get the preference and D2D pairs will share the resources with the cellular users. As sharing will induce co-channel interference between the CUs and the D2D pairs, we proposed a PSO based permutation optimization strategy to optimally share the resources between cellular users and D2D pairs, so that co-channel interference will be minimum and the system throughput gets maximized. We simulated our proposed strategy for different path loss models in LTE downlink network. Simulations show that our proposed strategy improves the overall system throughput.