## 1 Introduction  
Visible light communication (VLC) is emerging as a key technology in the field of wireless communications, offering significant advantages such as wide bandwidth availability, immunity to electromagnetic interference, and the potential for energy-efficient data transmission [1]. VLC systems utilize the visible spectrum, often relying on light-emitting diodes (LEDs) to transmit data while simultaneously providing illumination [2]. However, despite its potential, VLC faces several challenges in real-world environments, particularly in terms of maintaining reliable communication in the presence of obstacles that cause shadowing or block the line-of-sight (LoS) path between the transmitter and the receiver [3]. These challenges can drastically degrade the system's performance by reducing the received signal strength and causing interruptions in data transmission. In this context, one of the primary limitations of VLC systems is the dependency on LoS conditions for optimal performance. Objects, walls, or people can easily block the light path in indoor environments, leading to total or partial shadowing [4]. This issue becomes more pronounced when the user or receiver moves, further complicating the system's ability to maintain a consistent signal [5]. Moreover, reflections caused by indoor surfaces can result in multipath propagation, which can enhance or deteriorate the signal, depending on how it is received [6; 7]. This necessitates the development of innovative techniques that can mitigate the impact of shadowing and non-line-of-sight (NLoS) conditions while simultaneously improving spectral efficiency and ensuring reliable communication. To mitigate the aforementioned problems, in recent years, intelligent reflecting surfaces (IRSs) have gained significant attention as a transformative technology in wireless communication systems, including VLC [4; 5; 8]. An IRS consists of large arrays of passive reflecting elements that can dynamically control the phase, amplitude, and polarization of incoming waves, allowing for the redirection and enhancement of signals in a highly efficient manner [9]. By intelligently adjusting the reflection properties of each element, the IRS can be used to mitigate the effects of signal blockages, enhance coverage, and improve signal quality, especially in environments with obstacles or NLoS conditions [10]. The key advantage of the IRS is that it operates without requiring additional active power, making it a cost-effective and energy-efficient solution to improve communication performance [11]. Moreover, the flexibility in configuring the reflection pattern allows the IRS to adapt in real time to changing environmental conditions, making it an ideal technology for dynamic and complex indoor settings. On the other hand, angular diversity receivers (ADRs) offer another powerful solution to the challenges of VLC in obstructed environments [12; 13]. ADRs are equipped with multiple photodetectors arranged at various angles, allowing them to capture light from different directions and mitigate the effects of shadowing or signal loss [14; 15]. The advantage of ADRs lies in their ability to handle multipath propagation, which is common in indoor scenarios, where light can reflect off surfaces such as walls, floors, and ceilings. By combining the signals received from different angles, ADRs can improve the overall signal-to-noise ratio (SNR) and enhance data reception [16]. This capability is further enhanced when integrated with machine learning algorithms, which can optimize the selection and combination of received signals based on current environmental conditions [17; 18]. ADRs, therefore, provide a robust framework for reliable VLC reception in challenging scenarios with significant mobility or obstruction. Building on these technologies, the proposed work integrates IRS and ADR systems to address the challenges of VLC in environments with total or partial shadowing.