LiDAL-Assisted RLNC-NOMA in OWC Systems

Optical wireless communication (OWC) is a key enabler for immersive indoor data transmission in future wireless networks. However, managing multi-user interference remains challenging in dense indoor OWC deployments with multiple optical access points (APs) serving multiple users. In this paper, we propose a dual-function OWC system for communication and localization. For data transmission, we design non-orthogonal multiple access (NOMA) combined with random linear network coding (RLNC): NOMA serves multiple users simultaneously via power-domain multiplexing, while RLNC improves decoding robustness under residual noise and processing impairments. The system is assisted by a light detection and localization (LiDAL) module that estimates users' spatio-temporal presence and location to enable dynamic user association. LiDAL also supports channel state information (CSI) estimation in realistic indoor scenarios where CSI may be noisy and/or highly correlated. We evaluate RLNC-NOMA by analyzing the probability of successful decoding and comparing it with conventional NOMA and orthogonal schemes. In addition, we derive the Cramer-Rao lower bound (CRLB) to evaluate the localization accuracy. The results indicate that RLNC-NOMA increases the probability of successful decoding, and that the proposed unbiased location estimator achieves 44% better CSI accuracy than the baseline CSI estimation and improves the overall system performance.