A Distributed Coverage Adjustment Algorithm for Femtocell Networks

In two-tier femtocell networks, adjusting the transmission power values of femtocell base stations (BSs) such that indoor users receive high signal quality while limiting leakage to outdoor users is an important problem. This paper proposes a novel distributed and self-optimized power adjustment algorithm for two-tier femtocell networks, in which a BS adjusts the transmission power based on the signal quality of neighboring BSs. Achieving fairness among users with minimal information exchange is desired. There are no predefined target parameters used to adjust transmission power, contrary to existing approaches in the literature. The convergence properties of the algorithm under fixed and time-varying communication infrastructures are investigated. The performance is further verified by simulations and comparisons with other algorithms for the coverage problem.