System performance analysis of OFDMA-based femtocell networks

OFDMA femtocells have been proposed as a viable solution not only to deal with the explosive growth of traffic but also to increase energy efficiency of cellular network. However, the system performance of the two-layer femtocell networks is quite different from macrocell networks.In this paper, we first analyze the performance of hierarchical network in terms of system capacity and energy efficiency, especially in the case of introducing sleep mode according to variant network load. Then, we evaluate the users´ quality of service (QoS) under different factors, including the distance between macro base station (MBS) and femto base station (FBS), user location, FBS transmission (Tx) power and deployment density. The simulation results show that system capacity and energy efficiency can be improved significantly after FBS deployment and various kinds of factors have effects on users´ QoS to different degrees. Our research results provide useful guidelines for the deployment of OFDMA femtocell networks.