Distributed pricing power control for downlink co-tier interference coordination in two-tier heterogeneous networks

In this paper, we consider distributed power control schemes for downlink co-tier interference coordination in a two-tier heterogeneous network consisting of multiple femtocells under the coverage of a macrocell. We formulate a non cooperative game in order to solve this problem. First we propose an algorithm in which all femto access point simultaneously update their transmit power to maximize their individual payoff function according to a dynamic best response function. Numerical results show that in this non-cooperative game, all femtocells' transmit power converges quickly to Nash equilibrium points. Second, we develop a novel dynamic pricing power control scheme by using the update mechanism named gradient play to update the transmission powers of all femtocells. Numerical results show that the second proposal can attain lower transmission power but higher throughput in comparison with our first proposal, and both proposals outperform the conventional power control schemes.