5G Retro-Directive Quasi-Optical Lens Beamforming MIMO

This paper presents a beamspace MIMO dictated by the proposed quasi-optical lens with transceiver MMICs distributed on the focal plane in close proximity within the point spread of the lens, followed by a switching matrix module arbitrarily connecting p baseband units and n sets of transceivers. Ray-tracing diagrams explain the retro-directive channel propagation characteristics of the proposed quasi-optical beamforming MIMO, demonstrating that the returned signals from a remote terminal under interrogation will reach the nearby receiver in the focal plane, which points to a promising solution to green communications at more than one order of magnitude improvement in energy consumption for a particular case study.