# Simulation of an Indoor Visible Light Communication System Using Optisystem
## 2 Related Work  
Numerous VLC system-related issues are looked into in this literature review. In many applications, the fundamental idea of a VLC system using an LED source appears to be crucial [17, 18]. LED lighting can achieve lower power usage and a longer lifespan compared to previous illumination systems. Understanding the many visible light communication facets and simulating a VLC system model for additional performance study are the goals of this literature review. Understanding the core ideas of VLC, applications, and difficulties is necessary for this literature assessment. The other features examined included various subjects, including VLC's difficulties and potential, simulation software for VLC systems, video and audio transmission systems employing VLC, light-based LED encryption techniques, and VLC-based vehicle-to-vehicle communication. The data rate, range, LOS/NOLS, uplink, regulatory concerns, and interference are a few of the difficulties examined in the context of VLC systems for various applications [19, 20, 21]. The introductory study of the VLC system employing LED lights is researched in [22]. The authors created an experimental setup and talked about optical lighting and transmission. Based on their VLC tests, the impact of inter-symbol interference and reflection was examined. They also spoke about attenuation from reflection sites and transmission loss brought on by inter-symbol interference. They concluded a correlation between data rate and the FOV employed in VLC and suggested the possibility of high-speed data transfer at speeds up to 10 GB/s. The concepts of a VLC system utilizing white LEDs are discussed in paper [23], which also looks into the possible possibilities of power line communications and white LED interior communications for broadband access. To ensure that there is no blind zone in the room for data connections, the authors installed a VLC system for lighting and high data rate indoor communications. The following are some essential items mentioned in [23]:  
* When the receiver's coverage radius exceeds \(\sqrt{2}\) meters, the receiver gets at least one LOS signal. * The receiver must have a minimum field of vision that is \(25^{\circ}\) or more. * LOS path signals have higher powers as compared to reflected path signals. In [24], the authors reported the concept of VLC and its challenges and prospects. Using straightforward modulation methods, they described the fundamental setup of the VLC system and the performance analysis of visible light transmission. According to their research, LEDs have a signal-to-noise ratio greater than 40 dB and a bandwidth of several megahertz (MHz). The equalization procedure is one of many methods that can be utilized to increase the data rate. They described various strategies for providing data rates of 100 Mb/s and higher. Additionally, they consider multiple factors to increase data speeds, including optical filtering, transmitter and receiver equalization, and optical multi-input multi-output (MIMO) transmission. They examined these factors to determine how they relate to data rate before concluding and outlining potential difficulties. VLC needs equalization, complicated modulation, signal processing, or parallel communications to reach high data rates of up to 100 Mb/s. However, for real-time data transmission, the VLC with larger data rates complicates the system. The authors' work presented a simulation program for indoor VLC in [25]. For simulation, they employed the programs MATLAB and Simulink. The simulation application explains the various transmitter placements and wall reflections. The authors used a simulation tool to determine the light distribution, root mean square (RMS) delay spread, and received signal waveform while considering transmitter placements and wall reflections. They examined the illuminance distributions before looking at the RMS delay spread distributions for one and four transmitters. Additionally,they used MATLAB/Simulink to show the waveforms for non-return-to-zero (NRZ) - on-off Keying (OOK).