A Novel Spectrum Assignment Technique for Interference Mitigation in 4G Heterogeneous Networks

This paper proposes a novel frequency reuse scheme in a hierarchical cellular network using the long-term evolution (LTE) technology. Universal frequency reuse (UFR) is targeted for future generation multi-cellular wireless networks. However, current research has shown that implementation of UFR may lead to intolerable interference levels experienced by user equipments in the vicinity of the cell edge. In this paper, we specifically address this issue. In the proposed frequency reuse framework, the available subcarriers are partitioned into three bands and the cell is divided into two major partscell center and cell edge. The edge of the cell is further divided into three regions Interior Edge Band (IEB), Intermediate Band (IB) and Exterior Edge Band (EEB). The cell center uses all three frequency bands with low power and cell edge uses only one of three bands. As the proposed architecture contains well defined boundaries for the sub-bands, it is easy to deploy more femtocells at the cell edge and exploit all other frequency sub-bands that are not used. The proposed frequency reuse scheme is an effective inter-cell interference coordination (ICIC) technique for next generation wireless networks. Simulation results shows that the proposed scheme can perform better on cell edges, reduce transmission power, improve network capacity and cell throughput when compared with commonly used techniques like Soft Frequency Reuse (SFR) and Partial Frequency Reuse (PFR).