Diversity Based on the Vortex Wave in Fading Channels

This paper examines the diversity technology based on the vortex wave in wireless communication. Because the modes of orbital-angular momentum (OAM) carried by the vortex wave are orthogonal to each other, the signals received by the vortex wave antenna with multiple different OAM modes can be more independent of each other in the rich scattering environment. In this paper, the correlation of the signals received through multiple different OAM modes is analyzed under three typical channels. The results show that the OAM modes can be applied for diversity in wireless communication and can reduce spatial correlation. The comparison of the output bit-ratio-error (BER) performance between the vortex-wave-based diversity and the conventional space diversity is given with the different combining schemes. When the max-ratio-combination is used, the output BER of the vortex-wave-based diversity is equal to that of the conventional space diversity. The vortex wave offers an alternative diversity method. This application can avoid the vortex wave's shortcoming of the range limit in the wireless communication.