Interference Management Research In Two-tier Femmtocell Networks Based On Robust Power Control

Femtocell,also called “home base station”.The technology of femtocell plays an important role in solving the problem of indoor coverage,reducing the cost of cellular coverage and improving the quality of wireless communication.However,the random deployment of femtocell users and the spectrum sharing mechanism bring serious interference problem.So,the interference management in two-tier femtocell networks is an important issue,and power control is an important method to solve the interference problem.In the exiting algorithms to suppress the interference,most of these algorithms are based on deterministic wireless network environment.However,in the actual communication environment,the communication environment of wireless network is changing and unstable,which may lead to these existing power control algorithms can not be satisfied the design requirements of this system.Therefore,in this paper,a robust power control algorithm is proposed aiming at the uncertainty of two-tier femtocell networks.At the same time,the game theory is introduced to achieve the reasonable allocation of network resources and reduce the network overhead.Firstly,according to the uncertain channel gains of interference links,in order to guarantee the quality of service of all users,a robust power control algorithm based on probability constraints is proposed.A simple and novel power allocation algorithm is proposed based on the average signal-to-interference-plus-noise ratio.At the same time,in order to improve the utilization of network resources,an admission control algorithm is proposed.The simulation results show that the proposed robust power control algorithm can guarantee the macrocell users under the premise of communication quality and improve the quality of femtocell users communication.In addition,the admission control algorithm can effectively improve network performance.Secondly,according to the uncertain channel gains of the channel signal links,the uncertainty is described by the probability constraint.To satisfy the different service requirements and design objectives for marcrocell users and femtocell users,the framework of hierarchical game with a leader-follower model is adopted.In order to improve the robustness of this system and maximize the utility of all users,a robust hierarchical game algorithm is proposed.A distributed iterative power algorithm is used to reduce information exchange.The simulation results show that the proposed algorithm can guarantee the communication requirements of macrocell users and femtocell users,and has strong robustness.Finally,considering the uncertain channel gains in both signal links and interference links,the worst-case method is used to describe the robust problem under the premise of the actual communication situation.Due to the scarcity of spectrum resources,femtocell users use the non-cooperative game to maximize their own utility.Therefore,a robust power control algorithm based on non-cooperative game is proposed.In order to guarantee the communication quality of macrocell users,it is necessary to price the interference caused by the femtocell users,and suppress the excessive interference from femtocell users.The simulation results demonstrate the effectiveness of the proposed power control algorithm.