Space Division Multiple Access in Uplink Underwater Optical Camera Communication Based on Image Segmentation

Underwater optical communication (UWOC) is a promising technology for effective data transmission, nevertheless challenges like multipath interference, turbulence, and strong attenuation persist. Additionally, multiple access management represents a crucial issue to address for the realization of the so called Internet of Underwater Things networks (IoUT). In particular, uplink medium access control is a largely unexplored field, with performance of both known orthogonal and non orthogonal strategies being assessed only for basic scenarios. This paper introduces a novel uplink space division multiple access framework for underwater optical camera communication (UOCC), integrating image segmentation techniques to distinguish and process multiple users simultaneously. Spatial diversity enables initial users separation by position relative to the receiver, while segmentation enhances signal decoding efficiency at the pixel level. The proposed system is evaluated under realistic underwater conditions, addressing propagation impairments such as Gaussian blurring, intensity saturation and quantization artifacts. Simulation results validate the robustness and scalability of the approach, highlighting its potential to enable reliable multiuser communication in uplink scenarios.