A Novel Dynamic Beam Steering-Based Architecture for Ultra-High-Speed Indoor Optical Wireless Communication Systems

Abstract

Indoor optical wireless links offer the potential for high data rates due to the wide and unregulated bandwidth of the optical spectrum. However, achieving ultra-high data rates in such systems requires using narrow infrared laser beams to focus optical power on the receiver. While narrow-beam links can enhance communication performance by concentrating power more effectively, they are subject to stricter eye safety constraints that limit the maximum allowable transmit power as the beam becomes narrower. Moreover, narrower beams are more susceptible to misalignment between the transmitter and receiver, as well as blockage by opaque objects. These factors restrict the mobility and range of such systems, limiting their adoption in commercial applications. Consequently, considerable research has focused on developing new configurations for indoor optical wireless links that utilize narrow laser beams to overcome these limitations.

This thesis presents a novel architecture for indoor optical wireless communication, referred to as the dynamic beam steering (DBS) system, which is designed to localize and track a mobile user while delivering high average data rates via a single ultra-narrow laser beam. Different from other indoor infrared communication systems that utilize multiple narrow beams, the proposed design employs a single emitter and achieves tracking and coverage through beam steering. Initially, a discrete multistage spiral search approach is developed to estimate the initial user location with sufficient precision to meet tracking requirements in the next phase while minimizing delay. Then, a tracking algorithm based on discrete beam scanning is developed along a circular pattern, enabling the prediction of the direction of the user movement and ensuring coverage during each scan cycle without the location information of the user. With a single bit feedback from the user, this system supports real-time tracking and communications.

This work proposes a theoretical model for the proposed DBS system, outlining its design and addressing considerations for tracking user movement while maintaining ultra-high data rates. Computer simulations show average achievable data rates of up to 10Gbps over a 1.5GHz bandwidth for a randomly moving user, and the results are compared with existing architectures to highlight the effectiveness and simplicity of the proposed scheme.