Power allocation for device-to-device underlay communication with femtocell using stackelberg game

Device-to-device (D2D) communication and femtocell are introduced as underlays to the cellular systems by reusing the cellular resources, where Stackelberg game framework is well suited to jointly consider the utility maximization of the macrocell, D2D and femtocell. In this paper, we study transmit power allocation schemes for D2D transmitters and femtocell users to improve the performance of the system. In our scheme, macrocell system is considered as the leader while the D2D pair and femtocell system are considered as two followers who buy the same channel resource from the leader, forming a one-leader-two-followers Stackelberg game. After analysing the procedure, we first obtain the optimal price for the leader and the corresponding optimal transmit power for both followers. Then we propose an iterative power allocation algorithm(IPAA), which will finally construct a Stackelberg equilibrium. Finally, we perform computer simulations to study the performance of the IPAA. It is shown that the IPAA is effective in distributed power allocation and macrocell protection for the spectrum-sharing-based three-tier networks. To make it practical, we demonstrate the IPAA is also efficient in Log-Normal Shadowing Model.