Maximization of Millimeter-Wave LoS OAM Link Using Beam Steering and Partial Receiving

Orbital angular momentum (OAM) can provide an additional multiplexing degree for millimeter wave multiple-input multiple-output (MIMO) communication. However, the performance of OAM link will suffer a great loss in non-ideal propagation scenarios, i.e. misalignment and incomplete receiving UCAs, since the divergence of OAM waves. In this paper, a partial receiving and beam steering scheme is proposed to improve the performance of millimeter OAM-MIMO link. While the beam steering scheme can direct the OAM beam to the receiver area, the partial receiving scheme can derive the complete receiving matrix by partial antenna array elements and demultiplex OAM signals. Numerical results show that the partial receiving scheme based on beam steering greatly improves OAM propagation and the system capacity.