A Graph-Based QoS-Aware Resource Management Scheme for OFDMA Femtocell Networks

Recently, femtocells are expected to be densely deployed to meet the booming demands for wireless data traffic, which inevitably causes serious co-layer interference due to the unplanned deployment. Hence, how to efficiently combat interference while furthest guaranteeing the quality of service (QoS) becomes an open question. To address this issue, in this paper, we present a joint admission control and a resource allocation strategy for an orthogonal frequency-division multiple access-based femtocell network. Particularly, we consider the scenario, where users are classified into two types, of which high priority ones have priority to access the network and enjoy high-resolution video streams. To perfectly eliminate the colayer interference with limited spectrum while maximizing the number of users whose QoS requirements can be guaranteed, we formulate an integer nonlinear programming problem, followed by a graph-based algorithm with polynomial computational complexity to solve it. The basic principle behind the proposed algorithm is to first chordalize the given conflict graph, and then perform admission control with priority differentiation-based admission control sub-algorithm, followed by the final resource block assignment with maximum effect rank allocation sub-algorithm. Furthermore, we illustrate how our proposal could be implemented in the long-term evolution system. Finally, through extensive simulations, we show that our proposal outperforms other two schemes in terms of guaranteeing QoS requirements.