Game Theory Based Uplink Power Control for UL/DL Split Scenario in Small Cell Networks

In heterogeneous networks, the evolved NodeBs (eNBs) have different downlink transmission power and the power imbalance problem can not be avoided. In order to solve this problem, Uplink/Downlink (UL/DL) split for users in Cell Range Expansion (CRE) region of small cells has been proposed in 3GPP. UL/DL split users are connected with macro cells and small cells simultaneously. In this paper, we propose an uplink power control scheme based on game theory for UL/DL split users. In the scheme, the convex pricing function is an exponential pricing function of users´ transmission power, which reflects the interference that macro users are suffering from UL/DL split users. It can ensure that UL/DL split users will be penalized when they cause serious interference to macro users. The power control scheme based on non-linear convex pricing obtains more improvements than the linear one with numerical simulations. Furthermore, a Dynamic Power Adjustment (DPA) algorithm is added to the scheme in order to mitigate interference in uplink and to speed up the convergence process.