Spectrum allocation scheme based on Stackelberg game in two-tier HetNet

As the explosive growth of wireless date requirements, heterogeneous network (HetNet) has become an effective solution for improving the system performance such as the throughput. The femtocells are always arranged to share the spectrum with the macro base stations (MBSs). Thus, the co-channel interference leads to the degradation of the HetNet throughput. In this paper, we discuss the program of spectrum reuse in the two-tier HetNet, and the problem is defined as a Stackelberg game approach. The MBS is play as a leader and it releases a part of spectrum resource for femtocells to avoid intertier interference. And the femtocells provide services to fractional macro users (MUEs) in return. Therefore, the throughput can be improved by the reduction of the inter-tier interference. Compared with the former works, the prominent characteristic of the method in the paper is that the benefit relation between the leader and followers is not measured by the real money. Furthermore, considering the system throughput specifically, we define the utility of the femto base stations (FBSs) by the average throughput as same as the utility of the MBS, which is used to improve the overall throughput of the system. Moreover, the gradient descent algorithm is also applied to compute the Nash equilibrium as the range of variables become continuous. The simulation results indicate that the proposed algorithm can observably reduce the interference and enhance the throughput of the network.