Joint Radar-Communications via Laguerre-Gaussian Vortex Beams

The orbital angular momentum (OAM) technique has attracted much attention in wireless communications and radar applications. The OAM has theoretically infinite states that are also naturally orthogonal to each other. This feature is useful to enhance spectral efficiency in wireless backhaul networks and distinguish spatial targets without beam scanning. Leveraging upon these unique properties, we propose an OAM-based bi-static joint radar-communications (JRC) system for a millimeter-wave vehicular application. In particular, we employ a frequency diverse array for the bi-static JRC and Laguerre-Gaussian beam distribution for OAM. To recover radar parameters and communication symbols effectively, we design a multiplexing and diversity strategy to resolve the identifiability issues. Numerical experiments validate the effectiveness of our proposed technique.