Cooperative beamforming scheme using MIMO antenna array in LTE-A system

Beamforming (BF) technique using multiple input multiple output antenna array improves reliability, range of transmission, and cell capacity in the long-term evolution-advanced system. Especially, coordinated multi-point (CoMP) method based on the BF techniques has been studied to increase total cell capacity by reducing the inter-cell interference. If a downlink CoMP scheme is applied, more robust transmission is achieved to the user equipment located at the cell edge. There are several types of DL CoMP schemes already and system operator selects a proper scheme according to service property in a real wireless communication system. However, there is a trade-off between the reliability and the resource allocation. In this paper, the hybrid cooperative BF scheme considering this trade-off is proposed. The proposed scheme switches the transmission methods according to the channel state information. Consequently, this scheme can use resources more efficiently and the reliable transmission can be maintained even though a user is located at the cell edge.