An improved distributed iterative beamforming algorithm with cooperative base stations

In this paper, an improved distributed iterative beamforming algorithm is proposed for cooperative base stations, and the detailed characterizations with instantaneous and statistical CSI are presented. Firstly, virtual signal-to-interference- plus-noise ratio (SINR) instead of user rate is chosen as decision criterion to avoid feeding back message by users to tell the base stations which strategy should be initialized with and whether to terminate the iteration. Then, the number of iterations is decreased through solving a constrained optimization problem of maximizing the virtual SINR for a given level of generated interference to the other users which can be converted into a standard convex optimization problem and solved by tools of mathematical programming. Finally, the performance of the proposed algorithm is evaluated.