Abstract
Femtocells are the solution to improve cellular system capacity in indoor coverage. In two-tier networks, co-channel interference is a serious problem. In this paper, an efficient spectrum allocation scheme is proposed to improve signal to interference plus noise ratio (SINR) and the throughput for femtocell users. The proposed spectrum allocation scheme is based on reducing the cross-tier interference by allocating the best group of the available resource blocks (RBs) that achieve minimum interference level for femtocell users. The soft frequency reuse scheme is considered for long term evolution cellular system due to its ability to decrease the inter-cell interference and enhances the throughput for macrocells. Simulation results show that the proposed spectrum allocation scheme efficiently increases the SINR for femtocell users and enhances both the femtocell throughput and the total cell throughput compared to the conventional random allocation scheme. In addition, it is shown that the best performance of proposed scheme in terms of highest SINR and highest throughput is achieved by allocating only one-third of the available RBs for femtocell.