Flexible Soft Frequency Reuse Schemes for Heterogeneous Networks (Macrocell and Femtocell)

A mass deployment of femtocells is anticipated to affect a number of areas more adversely, especially in the cell-edge of the macrocell network. In this paper, we propose a flexible frequency-partitioning scheme for OFDMA network based on cyclic difference sets. The cyclic property of these sets allows a quick construction of orthogonal patterns for the macrocell network with an emphasis on tri-sector sites. The impact and the co-deployment of femtocells is also investigated. Unlike, with existing works in the literature, the novel scheme can adaptively control the level of coverage in the cell-edges areas and additionally enables coexistence of femtocells in the network. Simulation results confirm the effectiveness of the proposed scheme in both macrocell and femtocell networks compared to the legacy soft frequency reuse and universal frequency reuse.