# Simulation of an Indoor Visible Light Communication System Using Optisystem
## 2 Related Work
They suggested an M-sequence-based LED array detection approach and an inverted signal-based LED array tracking method. Their experimental results demonstrated that the system could establish error-free communication between 25 and 80 m while driving and that the receiver could detect and track precisely. In [35], the idea of a vehicle positioning strategy utilizing a VLC system is proposed. The authors outline a vehicle positioning system that usesV2V and V2I visible light communication in their work. A camera sensor extracts the location information of LEDs installed on the tunnel infrastructure and car tail lamp. The simulation results demonstrated that their suggested strategy might produce accurate positioning when a large number of pixels and a short distance from the LED light sources are supported. This model can be used as an alternative to the conventional GPS. Data transmission security is one of the main issues VLC systems encounter. To address data security concerns, the VLC systems now use light encryption. A new encryption method for visible-light communication is presented in [36]. This work suggests a light encryption system combining gadgets with LED and a camera image sensor receiver (Rx), such as mobile phones, palmtops, or laptop computers. The suggested light encrypter may receive the original visible light signal from the ceiling or desktop lamp; after that, the data can be encrypted using a private key or other cutting-edge encryption techniques. This light encrypter can then emit the encrypted signal as visible light. The light encrypter serves as an encryption gateway for signals in the optical domain. A positive intrinsic-negative (PIN) photodiode (PD), an avalanche photodiode (APD), or a smartphone camera image sensor can serve as the Rx in this light encrypter. The rolling shutter effect of the complementary metal-oxide semiconductor (CMOS) camera can be used to enhance the transmission data rate to a higher level than the camera's frame rate. Then, the data information can be obtained by demodulating the rolling shutter pattern (bright and dark fringes received by the camera). They also proposed and demonstrated a light encryption scheme using the Otsu thresholding scheme to define the data logic in the rolling shutter pattern. They discovered that employing 16 Otsu intervals was preferable at high illuminance situations. The proposed smoothing scheme can significantly enhance the BER by up to 2 orders of magnitude at high illuminance due to the reduction of ER fluctuation. In [37], the authors' used standard data encryption techniques followed by modulation of the signal using OFDM. LEDs are driven by the modulated signal, which sends a binary bit stream as light across the air medium. The broadcast signal is converted back into a usable form at the receiving end using a photodetector. A driver circuit and an appropriate decryption block are used on the receiver side to get back the transmitted signal. The authors showed an example by sending a grayscale image. On the receiver side, they reproduced the shared grayscale image. Their proposed system used LED bulbs to transmit data at a high rate. The OFDM modulation scheme is used for coding the grayscale image. The photodiode detects the LED blinking at the receiving end and reproduces the transmitted grayscale image. The authors suggested a brand-new data encryption system for visible-light communication in [38]. The authors present the effect of encryption and decryption in the indoor visible-light communication system. For encryption, they made use of the Rivest-Shamir-Adleman (RSA) algorithm. The bit error rate performance for both insecure and secure visible-light communication systems is also explained. It was discovered that the power penalties for a BER of \(10^{-4}\) were 2 to 4 dB in secured visible-light communication. The impact of key length on error propagation and the power penalty of indoor visible-light communication systems is also covered in their work.