Interference mitigation and capacity enhancement based on dynamic frequency reuse for femtocell networks

Wireless networks employing small cells like femtocells are considered to be the choice of network deployment for 4G or advanced networks. This hierarchical deployment of cells introduces the necessity of effective frequency planning for mitigation of interference between different layers of network. As the scarce spectrum resources are likely to be reused to increase spectral efficiency, interference free signal reception has to be guaranteed to ensure better quality of service (QoS). In this paper we propose a dynamic frequency reuse scheme for the deployment of femtocells within a macrocell with the femtocells reusing the spectrum of neighbouring macrocells. We also provide a protective scheme for cell edge femtocell users as they are vulnerable to interference signals from neighbouring macrocells. A detailed frequency planning is provided to maximize spectral reuse while providing maximum throughput. We compare our proposed scheme with other frequency allocation schemes already described in literature. Simulation results shows that our scheme provides better throughput and ensures lower outage probability.