Research On Power Control Based On Game Theory In Heterogeneous Networks

Recently, the fast development of wireless communication technologies has propelled the updating of mobile communication systems, making them ever closely relate to people’s life on every side. The human beings’exploration to-wards more advanced communication systems has never been halted. This thesis firstly reviews the development of the broadband wireless communication system from the3rd Generation Partnership Project (3GPP) to the Long Term Evolution Advanced (LTE-A) standard and introduces the rising of small cell networks. As a constituent of the heterogenous networks, small cell networks have undoubtedly benefited the network users greatly, but they have also brought in the interfer-ence problem between small cell base stations and nearby macrocell base stations, which has become one of the frontiers of current research for academia and in-dustry.In this thesis, by combining the advantages of both centralized regulation and game theoretic distributed optimization, a pricing-based power control scheme is proposed for the macro-femto heterogeneous networks. The proposed scheme, based on the pricing model, takes control of the downlink transmit power of fem-tocell networks. The scheme employs the theory of Stackelberg game (SG). The network interference controller (NIC) acts as the leader while the Home Evolved Node B (HeNB) it connects to play as the followers. The NIC tries to minimize the sum interference to the macrocell user equipment (MUE) through pricing for the HeNBs’power consumptions. With the price, HeNBs maximize their own utilities through a non-cooperative game. A unique Stackelberg equilibrium (SE) is verified to exist in this game. Besides, a distributed price and power iteration algorithm is further proposed and its convergence is also proven. Finally, the proposed vector pricing (VP) and the scalar pricing (SP) methods are simulated. Results show that both two methods reduce the sum interference from HeNBs to the MUE, and also improve the power efficiency of the network. Specifically, although the VP method reduces more transmit power of HeNBs than the SP method, the former one can better balance the transmit rate of the network by pricing uniformly for the users, which reflects the fairness of the system.