Impact of spreading on the capacity of neighboring femtocells

Interference between neighboring femtocells may have a critical impact on their performances. In this paper, impact of resource spreading is investigated on the capacity of two neighboring femtocell networks. It exploits the fact that at a given time, the number of active femtocell users may be much smaller than the maximum allowed, and the allocated spectrum may typically be under-utilized. The behavior of the capacities of two neighboring femtocell networks (one being under-utilized, and the other being fully-utilized) with respect to the spreading factor are analyzed for different interference conditions. Also, a rate-constrained resource utilization approach in the underutilized network is discussed. Through spreading the resources of the under-utilized femtocell, it is shown to improve the capacity of the fully utilized femtocell network in most scenarios.