By using narrow infrared (IR) beams, optical wireless communication (OWC) system can realize ultra-high capacity and high-privacy transmission. However, due to the point-to-point connection approach, a high-accuracy localization system and beam-steering antenna (BSA) are required to steer the signal beam to user terminals. In addition, to achieve link alignment in the receiver, the BSA needs to be within the limited receiver field of view (FoV). This problem greatly limits the practical application of high-capacity IR optical wireless communication and has not been well solved yet. In this paper, we proposed an indoor beam-steering IR OWC system with high-accuracy and calibration-free localization ability by employing a coaxial frequency modulated continuous wave (FMCW) light detection and ranging (LiDAR) system. In the meantime, benefit from the mm-level ranging accuracy of the LiDAR system, a feasible approach to deal with the link alignment issue for practical applications is firstly demonstrated. With the assistance of the LiDAR system, we experimentally achieved the localization of user terminals with a 0.038-degree localization accuracy, link alignment at the receiver and an error-free on-off keying (OOK) downlink transmission of 20 Gb/s in free space at 3-m distance is demonstrated.
Fully Passive User Localization for Beam-Steered High-Capacity Optical Wireless Communication System
