Power control based interference mitigation in multi-tier networks

Significant areal capacity gains and improved cellular coverage can be achieved by hierarchical deployment of Femto Access Points (FAP) over an existing cellular network. However, the introduction of FAPs, which use the same spectrum as the cellular network, can cause severe interference to network and drive users into outage. In order to resolve this issue, advanced interference mitigation (IM) techniques should be applied in multi-tier networks. In this paper, we design and evaluate power control based IM algorithms in cellular systems with femtocell overlay. Simulation results show that FAP power back-off helps lower macro-user outage probability at the cost of femto-user rate reduction. For control channels with low data rate requirement, FAP power control can be a potential IM solution.