Analysis of transmission capacity for multi-mode D2D communication in mobile networks

Device-to-device (D2D) communication is one of the promising technologies in the 5th generation of wireless communication (5G). This paper investigates the achievable transmission capacity for multi-mode D2D communication. By utilizing stochastic geometry tools, we first provide the system model and derive the transmission capacity for two different sharing schemes of underlaying D2D mode. The first one is that each cellular spectrum can be reused by single D2D pair and the other one considers the multiple sharing among several D2D pairs with the same spectrum. In addition, we analyze the strategy for the optimal selection between both different sharing scenarios. Secondly, we analyze the transmission capacity for overlay D2D mode. Finally, with the optimal relay selection strategy, the maximization of transmission capacity for relay-assisted D2D communication is obtained under the constraint of minimum energy consumption. Furthermore, simulations are carried out and the results demonstrate the effectiveness and validity of our analysis.