Orbital angular momentum beamforming for index modulation with partial arc reception

Abstract

A novel beamforming (BF) method for orbital angular momentum (OAM) index modulation (IM) scheme is proposed in this Letter. Since the OAM wave has an inverted cone-shaped beam structure, only partial phase plane can be received during long distance transmission. Based on this partial phase plane information, an OAM–IM system can be established. Since the receiver is only located on a partial arc of the cone-shaped beam, the energy of the whole beam cannot be fully received. However, by adjusting the combinations of multiple OAM beams, the energy of the cone-shaped beam will be converged to a specific direction where the receiver is located. Compared with the traditional BF method, as a new degree of freedom, the OAM–BF method can not only increase the flexibility of beam steering, but also realise the IM information transmission on the partial receiving phase plane.