Joint user association and reuse pattern selection in heterogeneous networks

The successful deployment of LTE heterogeneous networks (HetNets) depends crucially on the inter-cell interference (ICI) management. Among ICI coordination schemes, fractional frequency reuse (FFR) is considered as an efficient technique well-suited to OFDMA-based HetNets. Two coupled questions in this context are: how to associate users to appropriate basestations considering the long list of available candidate cells, and how to allocate frequency resources among multiple cells. In this paper, we treat the multicell frequency allocation as frequency partitioning among multiple reuse patterns, and develop a novel algorithm to solve these two coupled questions in a joint manner. We also provide practical criterion to select the set of essential candidate patterns from all possible patterns. Results show that the proposed joint strategy improves both the cell-edge user and overall network throughput.