Propagation Model for UCA-based OAM Communications in Six-Ray Canyon Channels

Orbital angular momentum (OAM) has attracted considerable attention as a novel solution for ultra-high spectrum efficiency wireless communications. However, researches have focused on the line-of-sight (LOS) scenario and the two-ray non-LOS model. In addition, the two-ray model cannot be applied to certain scenarios e.g. streets, valleys, tunnels, etc. To address this problem, we derive the propagation model of uniform-circular-array-based OAM communications in six-ray canyon channels. This paper gives a full investigation of the multi-path effects, including phase-front distortion, mode spectrum, and receiving power weighting. Numerical results show that the low-order OAM signal can obtain a better transmission gain than high-order OAM signal in multi-path environments. The proposed model can help research and application of OAM in future communication systems.