Optimizing Spatial Multiplexing in Hybrid Analog-Digital Wide-Aperture MIMO Systems with Spherical Wavefronts

The core message of this paper is to explore optimal spatial multiplexing for planar arrays equipped with a hybrid analog-digital architecture in line-of-sight (LoS) wide-aperture MIMO systems. The authors propose an optimal antenna configuration and a low-complexity analog-digital beam focusing scheme to achieve near-optimal spectral efficiency.