Uplink Power Control In Two-Tie Femtocell Networks

Femtocell is an important solution for improving the indoor coverage and capacity of thecommunication system. It is enabled by a Femtocell Access Point (FAP) that is connected to theservice provider via a third party backhaul, such as Digital Subscription Line (DSL) or cablemodem. The good characteristics (convenient installation, low-power and better indoor signalcoverage) of Femtocell make it attract numerous equipment firms and operators. However, atwo-tie Femtocell network is usually implemented by sharing the spectrum, there must exist thecross-tie interference in a two-tie network, so it needs power control for Femtocell users.This paper mainly studies the uplink power control in two-tie networks. Firstly weintroduces the characteristics of Femtocell power control and the basic principles of game theory,using game model to study power control algorithm, and then by solving the equilibrium of thegame model to calculate the optimal transmit power of Femtocell users. Two practical Femtocellnetwork models are investigated: sparsely deployed scenario and densely deployed scenario. Inthe sparsely deployed scenario, considering some Femtocell users’SINR fail to achieve the lowestrequirement after game equilibrium, a novel adaptive interference price control algorithm isproposed, more Femtocell users can be used by adjusting the interference price after equilibrium.In the densely deployed scenario, considering the mutual interference of Femtocell users, a newcost function is designed in the game model, and the new cost fuction not only make the gameconverge to a unique point, but also improve the performance of the Femtocell users.