## 1 Introduction  
Positioning services based on satellite coverage, such as global positioning system (GPS), cannot provide satisfactory performance in indoor environments, which hamper the use of applications such as autonomous vehicles or improving the manufacturing procedures in the framework of the industry 4.0 [1, 2]. During the last decades, this issue has been solved by considering radio-frequency (RF) systems such as WiFi [3, 4] or Bluetooth [5]. However, positioning based on these techniques is subject to competing for bandwidth in an overwhelmed spectrum, which may lead to interference and non-satisfactory positioning performance. Moreover, the lack of dense deployments of access points limits positioning to simple techniques, such as a fingerprint, while more complex schemes, e.g., based on trilateration or angle of arrival (AoA), cannot be employed. In this context, visible light communication (VLC) has been proposed as an alternative technology for providing accurate and satisfactory positioning services [6]. In contrast with the previously mentioned techniques, VLC operates in a wide and unregulated spectrum, and it can be considered as a reliable, low-cost, and green technology that can be widely deployed in indoor environments based on the concept of light-emitting diodes (LEDs). White LEDs have become widely used in indoor lighting due to their energy efficiency, long lifespan, and cost-effectiveness [7]. High-frequency modulated LEDs simultaneously enable visible light to be used for indoor communication, positioning, and security applications [8]. VLC technology not only meets daily lighting needs but also enables communication and localization [9]. At this point, notice that VLC offers several advantages, including anti-interference properties, strong confidentiality, and abundant frequency band resources, which is crucial compared to other commonly used parts of the spectrum assigned to communications that are becoming more crowded [10]. One interesting application of VLC is indoor visible light positioning (VLP), which takes advantage of the deployed LEDs as transmitters to determine the location of specific targets [11]. Indoor positioning is an evolving area of research that seeks an alternative to the limitations of satellite-based radio navigation systems in small spaces where centimeter-level accuracy is critical [12]. VLP also provides cost-effective solutions for indoor positioning, making it a valuable addition to urban lifelines within enclosed spaces [13]. In [14], [PERSON] et al. (2024) presented a robust method for simultaneous position and orientation estimation using VLC, without relying on traditional radiation pattern assumptions. Their work introduces a system employing ring-shaped LED arrays, optimizing LED distribution and improving the position accuracy in complex environments. Specifically, the weighted gradient of the signal-to-noise ratio (WG-SNR) between adjacent LEDs is evaluated for precise edge detection and integrated with the random sample consensus (RANSAC) algorithm to refine the estimation model by removing erroneous or unwanted reflections. This approach provides a balance of high precision and robustness, achieving processing times of up to 0.22 s, even under adverse conditions. In a parallel study, in [15], [PERSON] et al. (2024) proposed an advanced machine learning framework incorporating Nystrom kernel approximation to enhance 3D VLP systems. This approach not only improves the accuracy of the position estimation by integrating advanced machine learning techniques with traditional VLP methods but also addresses computational complexity in challenging environments. Their system achieves an exceptional average relative root mean square error (aRRMSE) of 2.1 cm, demonstrating the method's ability to overcome the limitations of previous approaches. Meanwhile, in [16], [PERSON] et al. (2024) conducted a comprehensive review highlighting recent advances in VLC-based indoor positioning systems.