Analysis of design parameter issues for next generation OFDMA downlinks

Inter Cell Interference (ICI) problem has received a significant attention by the researchers in recent times in 4G and 5G Orthogonal Frequency Division Multiple Access (OFDMA) cellular networks. The ICI mitigation strategies are also expected to play a key role in 5G networks to improve the capacity while minimizing ICI. Soft Frequency Reuse (SFR) is one of the ICI mitigation schemes that has been adopted by the emerging cellular deployments. SFR is a deployment issue and does not require any change in the standard specifications. SFR scheme requires three important design parameters namely, Signal to Interference plus Noise Ratio (SINR) threshold, power ratio and bandwidth partitioning ratio. Appropriate and optimal choice of these parameters plays a vital role in determining network performance. A combination of these parameters thus influences the performance of such networks. In this work, we investigate the impact of these design parameters on the successful deployment of SFR OFDMA network for real time service. We investigate the cell capacity performance in terms of number of users by appropriate choice of the design parameters. From the results, it is seen that the SFR gives better capacity, in an optimum range of the parameters, when compared against the reference scheme. Hence it is concluded that the optimal choice of the parameters is important and it is dependent on the objective of the system designer.