Cooperative interference mitigation for indoor dense femtocell networks

It has been predicted that the total mobile traffic in the world will have a ten-fold growth from 2011 to 2016. Moreover, it is estimated that over 80% of the mobile traffic is generated indoors. Massive indoor femtocells are expected to be set up for offloading indoor users from outdoor macrocells and to provide huge capacity to meet high data demands. However, inter-cell interference between femtocells is one of the major challenges in indoor deployments and needs to be addressed in the network planning phase. In this paper, interference mitigation schemes for indoor dense deployment of femtocells are investigated, and a cooperative transmission scheme and a semi-static interference mitigation scheme based on fractional frequency reuse (FFR) are developed for dense femtocell networks. Extensive simulations using a dedicated indoor network planning and optimization tool, iBuildNet®, are carried out to evaluate the proposed schemes. Simulation results show that the proposed schemes are able to yield significant gains in terms of average throughput.