An Iterative Algorithm for Downlink Multi-Cell Beam-Forming

In this paper, we address the problem of severe performance degradation of cell-edge users in conventional cellular networks via multicell processing with improved spectral efficiency. Using uplink-downlink duality, we propose an iterative multicell beamforming algorithm that minimises the total transmit power within a virtual cell of 3 adjacent sectors of 3 neighbouring BSs. We derive and employ a channel model that includes the angular spread caused by random local scatterers in the vicinity of a user. Simulation results confirm that the proposed algorithm converges fast to the optimal solution.