Fractional frequency reuse in LTE networks

Abstract

3GPP Long Term Evolution (LTE) is a standard for wireless communications to achieve high spectral efficiency, high peak data rates, as well as flexibility in frequency and bandwidth. By using frequency reuse of one in LTE networks, high spectral efficiency is achieved. However, the Inter-Cell Interference (ICI) resulted from the frequency reuse of one is a main limitation in these networks. Fractional Frequency Reuse (FFR) has been proposed as an Inter-Cell Interference Coordination (ICIC) technique in Orthogonal Frequency Division Multiple Access (OFDMA) based LTE networks. FFR divides the cell into an inner and an outer region, and then different frequency reuse factors are applied in each region in such a way the interference is reduced. This paper focuses on evaluating two FFR deployment schemes, namely, Strict FFR and Soft Frequency Reuse (SFR) and compares them with the conventional frequency reuse scheme. A broad comparison among all these frequency reuse schemes is performed by using a proposed mechanism which depends on Monte Carlo simulations considering performance metrics such as Signal to Interference plus Noise Ratio (SINR), capacity and throughput. Simulation results show that, the higher SINR achieved by Strict FFR is not reflected in terms of throughput due to the small bandwidth utilization, and Soft Frequency Reuse (SFR) can provide higher cell-edge throughput by increasing the power control factor but this comes at the cost of decreased inner region throughput.