Hierarchical-game-based algorithm for downlink joint subchannel and power allocation in OFDMA femtocell networks

Heterogeneous wireless networks are promising technologies to provide high-data rate services. Our study proposes a hierarchical joint subchannel and power allocation algorithm in orthogonal frequency division multiple access femtocell networks. FBSs and MBSs in the network maximize their capacity and compete with each other through resource allocation strategy. This competition is captured in the framework of a Stackelberg game, and the Stackelberg equilibrium is introduced as the solution to the problem. An iterative method is proposed for MBSs and FBSs to achieve the hierarchical Stackelberg equilibrium. We specifically recommend a new power allocation function for MBS. The best response strategy of MBS can be directly obtained by using the proposed power-allocation function. As a result, costs are decreased. We also divide the strategy of MBSs into two substrategies, namely, subchannel selection strategy and power strategy. The two substrategies interact with each other in the game process to improve the flexibility of the MBS strategy. A dynamic step-size mechanism is proposed to accelerate the algorithm. Simulation results are presented to show the effectiveness of the proposed algorithm under high-interference conditions.