Joint femtocell clustering and cross-tier interference mitigation with distributed antenna system in small cell networks

Femtocells overlaid onto macrocell constitute an underlay system instance of small cell networks whose performance is limited by cross-tier interference. This study proposes a cooperative cellular architecture composed of a distributed antenna system (DAS) and the femtocell-macrocell underlay system. By distributing the remote antenna units of the DAS, the cross-tier interference can be mitigated at the femtocells located near macrocell users using feedback signal from the DAS. The cross-tier interference mitigation is applied on femtocells clustered by the DAS. The proposed joint cross-tier interference mitigation and femtocell clustering ensures a better average capacity across all end-users in the two-tier network.