Analog-digital hybrid eigenmode transmission for massive short-range MIMO

This paper proposes an analog-digital hybrid eigenmode transmission technique for massive short-range MIMO, which utilizes both analog and digital beamformings. In this method, first, a channel matrix in a plane-symmetrically configured MIMO array is block-diagonalized by analog beamforming with hybrid couplers. Then, eigenmode transmission is virtually realized by digital beamforming toward each block-diagonalized sub channel matrix. This approach is geometrically realizable and results in a reduction in the required number of calculations.