Date Added: Mar 2010
The authors propose a new method for computing transmit beamforming vectors for downlink multi-cell Multiple-Input Multiple-Output (MIMO) networks. The key novelty of the work is the application of graphical model theory to the intercell interference problem. An index restriction beamforming strategy is adopted to mitigate intercell interference, and is implemented with the well-known message-passing algorithm known as belief-propagation. The advantage of combining restricted index beamforming with belief propagation is only local channel information is required, and the computational complexity is lower than competing methods for base station cooperation.