Extra DoF of Near-Field Holographic MIMO Communications Leveraging Evanescent Waves
Ran Ji, Shawn Chen, Chongwen Huang, Jun Yang, Wei E. I. Sha, Zhaoyang Zhang, Chau Yuen, Mérouane Debbah
Abstract
In this letter, we consider transceivers with spatially-constrained antenna apertures of rectangular symmetry, and aim to improve of spatial degrees of freedom (DoF) and channel capacity leveraging evanescent waves for information transmission in near-field scenarios based on the Fourier plane-wave series expansion. The treatment is limited to an isotropic scattering environment but can be extended to the non-isotropic case through the linear-system theoretic interpretation of plane-wave propagation. Numerical results show that evanescent waves have the significant potential to provide additional DoF and capacity in the reactive near-field region.