In this article, we present channel delay profiles based on simulated data regarding the practical conditions for the use of visible light communication (VLC) in automotive applications such as Intelligent Transportation Systems (ITS). Practical vehicular LED headlamp and street lamp that consider the lighting regulation for transportation are used to design the ITS scenarios based on VLC. We modeled two usage scenarios, crossroad and metropolitan street, using the CATIA V5 tool. Measurements for the VLC channel delay profile evaluation were then gathered by using a ray-tracing scheme employing commercial LightTools software under the vehicle-to-vehicle and vehicle-to-infrastructure (V2I) communication links. From the obtained channel impulse responses from both scenarios, we derived the VLC channel delay profiles. From them, we found that the common property of the delay profile was composed of dominant multiple line of sight (LOS) links and a less number of non-LOS delay taps. However, the channel delay profile for the V2I link and metropolitan scenario show more dispersive channel characteristics due to the reflection and diffusion of the visible light.

Visible light communication (VLC) is an emerging communication paradigm that supports illumination and data transmission simultaneously. To provide dimming control functionality, a range of dimmable modulation methods have been exploited. Among them, the variable pulse position modulation (VPPM) scheme, which is deployed using the IEEE 802.15.7 VLC standard is very simple and easy to implement. On the other hand, it has a limited data rate because it just uses binary PPM for data transmission. This study proposes the M ‐ary VPPM ( M ‐VPPM) scheme to increase the data rate of the VPPM scheme. To evaluate the performance of this scheme, the modelling of the transmitter, optical wireless channel and the receiver for M ‐VPPM are provided. In addition, the error probability according to the dimming ratio and modulation order was analysed mathematically. The simulation results showed that the analytical bounds on the error probability are tight, which provides key insights into the performance trade‐off of M ‐VPPM in a dispersive VLC channel environment.

Variable pulse position modulation (VPPM) is a new modulation scheme that supports simultaneously illumination with dimming control and communication. In this paper, the transmitter, optical wireless channel, and receiver structure of VPPM were modeled mathematically, and their error performance for examining the communication performance according to dimming level and data rate was analyzed. The results highlight the need for careful consideration of the tradeoff between the dimming flexibility and communication performance according to the channel condition in VPPM.

Demand for precise vehicle positioning (VP) increases as autonomous vehicles have recently been drawing attention. This paper proposes a scheme for positioning vehicles on the move based on optical camera communication (OCC) technology in the vehicle-to-infrastructure (V2I) environment. Light-emitting diode (LED) streetlights and vehicle cameras are used as transmitters and receivers respectively. Regions of streetlights are detected and traced by examining images that are obtained from cameras of vehicles. Then, a scheme for analyzing visible light data extracted from the images is proposed. The proposed vehicle positioning scheme uses information on angles between vectors that are formed under the collinearity conditions between the absolute coordinates of at least three received streetlights, and the coordinates of an image sensor. The experiments are performed under stationary state and moving state at a speed of 5 and 20 km/h. To verify the reliability of the proposed scheme, a comparison is made between the actual and estimated location of the camera in the stationary state. In addition, the path of a moving vehicle and the estimated path of the vehicle are compared to check the performance of the scheme. The performance of the proposed technique is analyzed and experimental demonstration confirms that the proposed OCC-based VP scheme achieves positioning accuracy of under 1 m.

Electronic displays and cameras can provide an intuitive, simple communications interface without dependence on additional wireless interfaces or the Internet infrastructure. In this paper, we design a complementary color barcode-based optical camera communication (CCB-OCC) system to provide an easy-to-use communication capability from an electronic display-to-camera (D2C) link. The proposed method encodes information into specially designed color barcodes and transmits it in a format perceptually invisible to humans but detectable by camera-equipped devices. In addition, we propose a new transmission packet design that contains pilot symbols to synchronize symbol packets and estimate the D2C channel link for calibrating captured images caused by irregular differences between the sending color and the receiving color in the D2C link. Experimental results verify the feasibility of the CCB-OCC scheme for short-range communications to offer additional information which shows a new possibility in designing a D2C communication system with robust to environmental change, easy-to-use, and simple implementation.