Virtual cell association and multi cell scheduling in ultra-dense networks

This paper considers the virtual cell(VC) association and multi cell scheduling in Ultra-Dense Network for sum-rate maximization where multi dimensional resources allocation strategy is coupled and interference environment is complex. For virtual cells association, a metric is proposed which is transformed from the non-convex problem via a series of decouples and captures the gain of multi user diversity and balanced cooperation strategy. For multi-cell scheduling, a graph-based framework is proposed, where users are firstly partitioned across different groups according to an edge weight which is proportional to the inter-cluster interference price, then greedy scheduling are carried out within each group to cope with the residual inter-VCs and intra-VCs interference. Simulation results confirm that the proposed association algorithm outperforms the reference algorithm. The results also show that the proposed user clustering with balanced strategy will prevents the complex interference from overwhelming the cell-splitting gains in Ultra-Dense Network.