Indirect Diffused Light Free-Space Optical Communications for Vehicular Networks

In this letter, we propose a novel indirect diffused light free-space optical communications (ID-FSOC) system based on laser light. This ID-FSOC system aims to provide high-speed (i.e., ≥1 Gbps) Internet access to vehicles. This approach extends the FSOC reach to locations that are out of sight from the transmitter. The proposed communications system employs diffuse reflectors (DRs) to uniformly emit diffused incident laser light in all directions, except toward the DR, which enables the receivers to receive the diffused light despite having no direct line-of-sight (LOS) to the transmitter but only to the DR. In our approach, LOS is required between the transmitter and the DR and between the receiver and the DR. We model the received power of the diffused light and estimate the power and bit error rate as perceived by a moving vehicle. Furthermore, we introduce possible operation modes to realize full duplex communications with ID-FSOC. Our results show the relationship between the transmission power and the DR-receiver distance and show that high data rates are achievable on practical DR-receiver distances.