Interference fair and multi-dimensional cooperation aware virtual cell forming algorithm for ultra dense network

Virtual cell can be foreseen as an effective way to solve the challenges in the ultra-dense network (UDN) which manifests as one of key technologies for 5G system. However, with the increasing density of network, the interference scenario becomes more complex, and user centric virtual cells are more likely to be overlapped. This situation made the multi-dimensional cooperation much difficult due to the coupled nature of different resource dimensions and the complexity of the optimum solution. In this paper, a novel scheme is proposed to tackle the two challenges highlighted above by virtue of virtual cell forming approach and subsequent resource allocation. The proposed scheme exploits multi-dimensional cooperation gain in the virtual cell forming stage by virtue of a graph edge weight design, which captures the contribution from interference fair power allocation, MU-MIMO operation and cooperative transmission. Based on the edge weight, virtual cells are formed by a clustering algorithm named Pairwise Maximum Weights (PMW). The proposed scheme allows the advanced power allocation and MU-MIMO operation in the subsequent resource allocation when users are jointly scheduled. The simulation result demonstrates that the proposed algorithm can increase the system performance effectively at a low complexity compared with the reference scheme.