Femto-Cell Resource Partitioning

This paper studies the impact of a femto-cell underlay deployment that shares radio frequency resources with urban macro-cells. Femto-cells promise substantial gains in spectral efficiency due to an enhanced reuse of radio resources. However, owing to their random and uncoordinated deployment, they potentially cause destructive interference to macro-cells and vice-versa. In order to maintain reliable service of macro-cells, it is most important to mitigate destructive femto to macro-cell interference. In the downlink, this can be achieved by dynamic resource partitioning, in the way that femto base stations (BSs) are denied access to resources that are assigned to nearby macro mobile stations (MSs). By doing so, interference to the macro-cells is effectively controlled, at the expense of a modest degradation in femto-cell capacity. The necessary signalling is conveyed through the wired backbone, using the downlink high interference indicator (DL-HII).