Performance Analysis Of D2D Assisted Cellular Networks With Power Control

With the development of wireless communications, people put forward higher requirements on the data transmission rate, spectrum utilization and energy efficiency of the communication system. Due to its characteristics of near-field direct communication, D2D(Device-to-Device) communication can significantly improve the transmission rate and energy efficiency, meanwhile reducing communication delay, which has aroused widespread concern of industry and academia. However, introducing D2 D into cellular networks may lead the system interference more complex. Therefore, the proper power control is used to coordinate interference and become the main research problem in the D2 D assisted cellular network.Firstly, the performance of heterogeneous cellular networks uplink is analyzed in this paper. Poisson point process is used for system modeling, where the cell coverage area with PVT(Poisson-voronoi Tessellation) random segmentation is proposed. Considering distance-proportional fractional power control scheme, the analytical expressions of link outage probability, average transmission rate and energy efficiency are derived. The analysis shows that the average transmission rate decreases with the increase of the power control factor.For the coexistent D2 D and cellular networks, when the overlay mode is selected, there is no interference between D2 D links and cellular links. Considering the distance-based D2 D mode selection and fractional power control scheme, we analyze the impacts of mode selection threshold and power control coefficient on the network performance. In this paper, we find that when the mode selection threshold become higher, the outage probability of D2 D links will be higher and the average transmission rate will be lower.Finally, this paper discusses the underlay mode, where there exists interference between D2 D links and cellular links. In addition to mode selection, channel inversion power control and constant power control schemes are performed by cellular users and D2 D users, respectively. The analysis results show that the uplink average transmission rate and energy efficiency of cellular user are decreased with the increase of the channel inversion power control coefficient.The analysis conclusions of this paper have some guiding significance for the system design and interference management of D2 D assisted cellular networks.