Semi-dynamic cooperative cluster selection for downlink coordinated beamforming systems

Coordinated multi-point (CoMP) transmission can significantly improve the spectral efficiency of cellular networks. To reduce the training overhead and the complexity for implementing CoMP, an effective way is to divide base stations (BSs) into cooperative clusters. However, with disjointed clusters, the cluster-edge users suffer from inter-cluster interference. In this paper, a scheme is designed to select a set of BSs to serve each user with CoMP coordinated beamforming, where the clusters of different users may overlap. To reduce the signaling overhead, the average net throughput of the network is maximized considering the training overhead. The proposed scheme depends on large-scale channel gains and can be operated in a semi-dynamic manner. A low complexity algorithm is proposed to form the clusters, which achieves similar performance to the optimal solution with exhaustive searching. Simulation results show the proposed algorithm outperforms the existing CoMP joint transmission with dynamic clustering and the Non-CoMP system.