Hypergraph-based frequency reuse in dense femtocell networks

Femtocell has been a valuable solution for cost-effective and high-capacity indoor cellular access. With rapid and dense deployment of femtocells, inter-femtocell interference arises as one of the major technical challenges. Conventional graph-based frequency reuse can only mitigate the interference from individually strong interfering nodes, but not the cumulative interference from multiple nodes (the individual interference from each can be weak). In this work, we propose a hypergraph-based frequency reuse scheme in femtocell networks. The scheme takes into account the cumulative interference by constructing hyper-edges in the graph and, hence, it can capture the actual interference more accurately in dense femtocell networks. Then with a heuristic coloring of the interference hypergraph and proportional frequency subbands allocation, spectrum is reused efficiently in the whole network. Simulation results show that the Signal-to-Interference-plus-Noise-Ratio (SINR) of users is improved and the throughput per femtocell is enhanced significantly by using the proposed scheme compared with conventional frequency reuse methods.