Optical-RoI-Signaling for Vehicular Communications

Abstract

This paper introduces a new hybrid waveform for optical wireless communication (OWC)/optical camera communication (OCC) systems and discusses the technical considerations of these systems. In a challenged vehicular communication environment, which requires high-speed, high-mobility, and long-distance communication support, implementing a hybrid waveform guarantees high-speed data transmission while reducing the cost of the OWC/OCC systems. The application of a hybrid waveform in the OWC/OCC systems is known as the region-of-interest (RoI)-signaling technique. This technique allows the OWC/OCC systems to simultaneously transmit low-rate and high-rate data streams. The low-rate data stream is used to detect and track the RoI of light sources for setting up the communication link, whereas the high-rate data stream is used for high-speed data transmission. Selection of proper modulation schemes for two simultaneous data streams is also discussed in this paper. A new modulation scheme, such as spatial-2-phase-shift-keying (S2-PSK), is proposed for the low-rate data stream. This scheme has been used to modify the IEEE 802.15.7-2018 standard, which is the revised version of the IEEE 802.15.7-2011 standard. For the high-rate data stream, single-carrier modulation or multiple-carrier modulation, such as the proposed hybrid-spatial-phase-shift-keying (HS-PSK) or variable pulse-position modulation (VPPM), can serve as viable solutions. Technical considerations for the modulation schemes of each type of data stream are analyzed to determine the feasibility of the proposed schemes. Finally, the experimental results and numerical parameters of the intended system are presented.