Less is more: Creating spectrum reuse opportunities via power control for OFDMA femtocell networks

Femtocell is a promising technology which can significantly improve the spectrum efficiency and system capacity of wireless cellular network. However, densely and randomly deployed femtocells may experience server inter-femtocell interference due to rough-and-tumble spectrum reuse with unconstrained power. Different from traditional macrocells, there is no central controller available for femtocells. Besides, static planning approaches is not workable here due to the random network topology. Taking downlink power control into account, we propose a flexible spectrum reuse scheme to handle the inter-femtocell interference and improve spectrum efficiency. The power control problem is modeled as a Nash Equilibrium Problem (NEP) and we employ Variational Inequality (VI) theory to analyze it. A distributed resource-aware power control algorithm is proposed to create spectrum reuse opportunities for femtocells interfering each other. Numerical results suggest that significant throughput improvement is acquired and the Nash Point can be reached within a few iteration times.