Experimental demonstration of LED-to-LED visible light communication between a traffic light and a vehicle headlamp

(2025) 2025:28 Park and Kim J Wireless Com Network https://doi.org/10.1186/s13638-025-02457-w EURASIP Journal on Wireless Communications and Networking Open Access RESEARCH Experimental demonstration of LED‑to‑LED visible light communication between a traffic light and a vehicle headlamp Se‑Jin Park1 and Sung‑Man Kim1*    *Correspondence: 1 Department of Electronic Engineering, Kyungsung University, Nam‑Gu, Busan 48434, Republic of Korea Abstract Visible light communication (VLC) technology using light-emitting diodes (LEDs) is currently being discussed to solve the problem of oversaturation in radio frequency (RF) bands. We conducted this study due to a lack of research on LED-to-LED VLC in the context of vehicle communication. One of the VLC technologies, LED-to-LED VLC, is a technology that applies LEDs to both a transmitter and a receiver. In this study, we demonstrate LED-to-LED VLC technology between a vehicle headlamp and a traffic light. We employed LEDs of different colors in the receiver and analyzed the theoretical channel capacity by measuring the 3-dB bandwidth, signal-to-noise ratio (SNR), and channel capacity. The communication performance was confirmed by measuring the bit-error rate (BER) as a function of the data rate. Studies have demonstrated that LED-to-LED VLC is feasible in the field of vehicle communication and is anticipated to be utilized for communication or data collection on the road. Keywords: LED-to-LED VLC, Optical wireless communication, Visible light communication, Vehicle communication, Signal-to-noise ratio 1 Introduction The growing use of personal electronic devices and the rapid development of mobile communication technology are increasing the demand for wireless data capacity, which has led to the need for more frequency bandwidth. However, the current RF band is supersaturated, and with the development of communication technology, the mm band is also expected to become supersaturated soon. Therefore, optical wireless communication (OWC) technology using infrared (IR), ultraviolet (UV), and visible light (VL) band has been actively studied as an alternative to this frequency supersaturated state [1–4]. OWC technologies includes various technologies such as visible light communication (VLC), light fidelity (Li-Fi), optical camera communication (OCC), and free space optical communication (FSOC). VLC, one of the OWC technologies, is a communication technology using visible light bands. VLC uses light-emitting diodes (LEDs) or laser diodes (LDs) as transmitters and photodiodes (PDs) or image sensors (ISs) as receivers. The block diagram of a typical VLC system is shown in Fig. 1. © The Author(s) 2025. 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To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/. Park and Kim J Wireless Com Network (2025) 2025:28 Fig. 1 Block diagram of a typical VLC system VLC systems are being studied in various fields such as internet of things (IoT), software-defined radio [5], indoor positioning system [6], vehicle-visible light communication [7], and optical-frequency conversion [8]. VLC technology offers several advantages such as wide bandwidth, no electromagnetic interference (EMI), easy implementation of the technology and high security. LEDs are being used in many places because of their longer lifespan and lower power consumption compared to conventional fluorescent lamps. With LEDs already installed in many places as transmitters, VLC can be implemented economically. However, commercialization of VLC technologies is not fast. We think that one of the main reasons is that VLC requires PDs or ISs for reception. Although LEDs are already installed in many places, we need to install additional hardware, PDs or ISs, as receivers of VLC. Therefore, we studied LED-to-LED VLC, which is a more economical way to implement VLC. LED-to-LED VLC is a VLC technology that uses LEDs as both a transmitter and a receiver. LEDs consists of PN junctions, like PD, so they can operate as light-emitting devices as well as light-receiving devices. LED functions as a light-emitting device when forward bias is applied. However, if reverse bias or zero bias is applied, LED can function as a light-receiving device like a PD. LED-to-LED VLC system is a low-cost VLC technology that does not need additional optical receivers such as a PD or a IS. Recently, several LED-to-LED VLC technologies that use LEDs as both transmitters and receivers has been studied [9–11]. Multipleinput multiple-output (MIMO) LED-to-LED VLC with RGB colors has been studied [12]. In [13–15], LED-to-LED VLC systems in both half-duplex and full-duplex modes were studied. In this work, we utilize LED-to-LED VLC technology in the vehicle communication. With the development of autonomous driving technology of automobiles, we expect that there will be a need for vehicle communication. However, vehicle communication also relies on limited RF bands, with numerous studies focusing on technologies such as advanced driver assistance systems (ADAS) [16] and dedicated short-range communication (DSRC) [16]. Therefore, in recent years, research has been actively conducted to address the issue of RF band supersaturation by applying visible light communication to vehicle communication and adding optical elements such as PD and IS to the receiver. These studies include infrastructure-to-vehicle (I2V) [17], multihop vehicle-to-vehicle (V2V) [18], traffic light-to-vehicle VLC [19], V2V VLC [20], and camera-based vehicular VLC [21]. Research has been conducted on the feasibility and application of LED-based VLC systems in vehicle communication [22]. In [22], a study focused on a VLC system designed with an LED transmitter and a photodetector receiver. Additionally, a study has conducted an experiment on a VLC system using vehicle headlamps as the transmitter and a photodetector as the receiver [23]. In [23], Page 2 of 12 Park and Kim J Wireless Com Network (2025) 2025:28 experimental results confirmed that communication at 10 kbps is possible over a dista (...truncated)