On compressive CSI feedback beamforming scheme for FDD massive MIMO
Massive MIMO is a promising technology in future wireless communication networks. To fully utilize the spatial multiplexing gains of massive MIMO, the channel state information (CSI) must be obtained as accurately as possible at the transmitter side. However the conventional CSI feedback schemes are not suitable for FDD massive MIMO because of reference signal and feedback overhead. In 3GPP Rel.13, the channel quantized codebook feedback scheme is employed in order to reduce the CSI feedback overhead. However the cost of this scheme is that the performance gain decreases dramatically due to the channel quantized error caused by the codebook feedback. In this paper, the channel sparsity of massive MIMO is analyzed and the compressive feedback beamforming scheme for FDD massive MIMO is proposed. The simulation results demonstrate that the proposed scheme can achieve the considerable performance gain.