Interference Coordination Method and Performance Analysis in Ultra-dense Network (UDN)

In ultra-dense Networks (UDNs), full frequency reuse can improve the network throughput. However, severe inter-cell interference (ICI) degrades the experience of the cell edge users. To ensure the user experience at any location, it is crucial to investigate how to coordinate ICI effectively to improve the data rate of cell edge users. In this paper, we study two typical interference coordination methods, random interference coordination and topology-based interference coordination. We derive their average data rates and the data rates of cell edge users. Analytical and simulation results show that random interference coordination can improve the signal to interference and noise ratio (SINR) of cell edge users, but cannot improve their data rates. It indicates that simply increasing the reuse factor cannot improve the performance of cell edge users, meanwhile causes the loss of average data rate. By contrast, the topology-based interference coordination can enhance both the SINR and the data rate of cell edge users simultaneously. When frequency reuse factor is low, we can improve the data rate of cell edge users considerably at the cost of little loss of average rate. By increasing the frequency reuse factor, it can achieve a good trade-off between the average data rate and the data rate of cell edge users.