Implement On Inter-cell Interference Coordination Scheme In Femtocell Network

Femtocell technology is proposed by the 3GPP for solving the ever growing demand of data traffic in cellular network. Home base is a low power, low cost, small-scale base station that can be installed by end user. Because of these features, the deployment of home base stations in cellular faces many new technical challenges, one of the most important things is how to mitigate all kinds of interference in the network.In general, the cellular network with the home base station is a two-layer network, the first one can be understood as a conventional cellular network, the second one is composed of small-range coverage, and randomly-distributed small cells. As recommended by the 3GPP, the home base can occupy particular partition of the spectrum or share the same partition with the macro base.Therefore, there exists two types of interference in the network, one is cross-layer interference because of sharing the same frequency between femtocells and macro base stations,the other is co-layer interference between users in femtocells or in macro cells. It is the complex interference in this heterogeneous network that makes the research of femtocell a hot topic.On the basis of traditional solutions, two improved schemes are proposed in this paper for solving the interference in the femtocell network to optimize the performance of the home base station network.(1) For the scenary of the deployed-densely home base stations, because the distance between the home base stations is so small that the interference between users is very serious, the paper proposes a solution for solving such interference. The scheme, based on the interference level of users, firstly divides users into different clusters, then the users in different clusters are assigned different frequency spectrums, while the user in the same cluster will share the same frequency spectrum, so as to minimize the interference.(2) On the basis of previous studies, a more optimal solution is proposed to mitigate the cross-layer interference in heterogeneous network. Compared to the previous schemes, this scheme optimizes the system throughput and user fairness.