**1.1 Visible light communication (VLC)**

Visible light communication (VLC) is an emerging technology that is intended to enable high-speed data transmission. It operates in visible band (390 nm-700 nm) and uses an LED or LD as a transmitter. The bandwidth available in the visible light spectrum is 390 THz, which is 1300 times greater than the bandwidth of radio frequency (RF) shared by many applications [1, 2]. The massive increase of mobile data traffic leads to saturation of the available RF communication bandwidth, which leads to a decrease in the quality of service. Considering the saturation of RF communication bandwidth, a complementary solution is required. VLC is one of the most promising alternative candidates to provide an additional spectrum. It simultaneously offers illumination, communication, and localization [3, 4]. In 5G/6G communication, the VLC system is one of the forthcoming candidates for indoor wireless access. It offers several advantages over existing wireless communication systems, such as high bandwidth, worldwide availability, network

**Figure 1.** *The possible application scenarios of VLC [9].*

security, and unlicensed bands. VLC satisfies the growing demand for wireless data communication. Therefore, it has been proposed to be used in vehicle-to-vehicle communication [5], indoor communication [6], wireless local area networks, wireless personal area networks, and underwater wireless optical communication (UWOC) [7, 8]. The possible application scenario of VLC is shown in **Figure 1**.
