Stochastic geometry based interference alignment in two-tier heterogenous cellular networks

Conventional cellular networks are gradually becoming heterogeneous due to deployment of femtocells within cellular networks. Femtocells have been considered by the wireless industry as a promising solution not only to improve indoor coverage and capacity but also to unload traffic from already overburdened macro base stations. Therefore, effective mitigation of both cross-tier and co-tier interference is a major design challenge hetereogenuous cellular networks. In this work stochastic geometry based model is developed for two-tier (macro-femto) heterogeneous cellular networks by using Matern hardcore point process leveraging results on Voronoi tessellations. Complex system level simulations are used to evaluate SIR performance, coverage and capacity of networks. This paper considers fractional frequency reuse to mitigate co-tier and cross-tier interferences. Simulation results confirm significant improvement in coverage, and capacity of the networks using proposed model.