Multi-Stream Multi-User Coordinated Beamforming for Cellular Networks with Multiple Receive Antennas

Multi-cell coordinated beamforming (CB) can mitigate inter-cell interference. However, existing work on CB focuses on systems that maximize overall throughput. This paper considers CB for systems with multiple receive antennas and further extends the CB to multi-user and multi-stream transmission. We take fairness into consideration and pay close attention to cell-edge users. CB that maximizes the harmonic-sum of signal-to-interference-plus-noise ratio (SINR) can be derived into a low-complex algorithm that favors cell-edge users. Two iterative algorithms are developed. From the simulation results, the proposed algorithms can provide a better 5-th percentile user throughput compared with the CB algorithms minimizing meansquare error, maximizing uplink SINR, and maximizing weighted sum rate. Furthermore, the computational complexity of the proposed algorithms is significantly lower than that maximizing the minimum SINR of users.