Opportunistic Multi-Beamforming in Multiuser MISO System

The opportunistic beamforming system can achieve the same throughput with channel singular value decomposition, and doesn't need perfect channel-state information. Opportunistic multi-beamforming improve system throughput by transmitting orthogonal beam, when increasing transmit beam number, the space-reuse gain will improve and the interference between beams will increase, which is contradict. To obtain the optimum number of transmitting beams, the paper analyze the throughput of MISO opportunistic beamforming system's capacity when adopt different number of transmitting beams. The results show that the optimum transmitting beam number is increased with users number, decreased with the average SNR.