Fast cell selection for femtocell based access networks

Fast Cell selection (FCS) is a well known technique for CDMA systems that provides site diversity to mobile terminals. However FCS is not used in current OFDMA based systems for practical reasons. This paper presents a possible strategy for introducing FCS into such systems. Time synchronization is required among cells, and FCS can be viewed as a particular case of joint scheduling for an active set of cells serving a given terminal. The particular case of femto-cell based and OFDMA based systems is specifically addressed as simplifications can be assumed in this context in order to simplify FCS introduction. Femto-cell based access networks are also known to have interference mitigation needs, at least when femto-cell are reusing macro-cell frequencies. FCS is also studied with this concern in mind. An analytical study is shown to bring significant performance improvement to OFDMA based and femtocell based cellular access networks. This study assumes an hybrid mode femtocell access and opportunistic scheduling techniques.