A comprehensive optimization framework for indoor laser-based optical wireless communication using gimbal-steered transmitters

The growing demand for high-speed wireless communication, driven by data-intensive applications such as high-definition video streaming and augmented reality, has highlighted the limitations of the Radio Frequency (RF) spectrum. Optical Wireless Communication (OWC) has emerged as a promising complementary technology, offering wide bandwidth, license-free operation, high security, and immunity to electromagnetic interference. Among OWC transmitters, Laser Diodes (LDs) provide high modulation bandwidth and narrow divergence angles, enabling data rates of several tens of gigabits per second. However, the narrow beam of LDs requires precise Line-of-Sight (LoS) alignment, making beam steering essential. This study focuses on optimizing the positioning and orientation of gimbal- or galvo-based LD transmitters in indoor OWC systems to minimize outage probability under LoS constraints and physical obstructions. An outage probability model considering room geometry and device field-of-view angles is developed and analyzed for three scenarios within a 7 × 5 m room: an empty environment, a room with a 1 × 1 m column, and a user-occupancy-aware environment. The complex optimization problem is solved using multiple meta-heuristic algorithms, including Particle Swarm Optimization (PSO), L-SHADE, and Stochastic Fractal Search with Fitness-Distance Balance (FDB-SFS). The obtained results are subsequently validated through grid search approach. The proposed approach achieves significant outage reduction, demonstrating that incorporating obstacle and user-distribution information enables efficient coverage with fewer terminals, reaching outage probabilities as low as 0.4%.