A Comprehensive Modeling of Vehicle-To-Vehicle Based VLC System under Practical Considerations, an Investigation of Performance, and Diversity Property

In this work, a vehicle-to-vehicle (V2V) visible light communications (VLC) model for two practical scenarios, is proposed. In scenario 1, the random lateral shift of vehicles and the deterministic longitudinal separation between two communicating vehicles are considered, whereas in scenario 2, longitudinal separation between two vehicles is considered to be random, and lateral shift of vehicles is considered to be deterministic. To this end, we emphasize comprehensive modeling of the practical characteristics of the considered V2V-VLC system, such as random path loss due to the random mobility of the vehicle, random lateral shift and random longitudinal separation of the vehicle. Moreover, we analyze the performance of the proposed V2V-VLC model in terms of different metrics under the consideration of a novel channel model. Considering our findings, it is observed that the random lateral shift of the vehicle and the random longitudinal separation between two vehicles have a significant impact on the V2V-VLC system performance. Further, at a distance of 40 m, for example, the path loss penalties for moderate and dense fog weather scenarios are 2 and 3 dB, respectively, compared with the clear weather. Furthermore, the combined impact of path loss and atmospheric turbulence affects the V2V-VLC performance significantly

The COST IRACON Geometry-based Stochastic Channel Model for Vehicle-to-Vehicle Communication in Intersections

Vehicle-to-vehicle (V2V) wireless communications can improve traffic safety at road intersections and enable congestion avoidance. However, detailed knowledge about the wireless propagation channel is needed for the development and realistic assessment of V2V communication systems. We present a novel geometry-based stochastic MIMO channel model with support for frequencies in the band of 5.2-6.2 GHz. The model is based on extensive high-resolution measurements at different road intersections in the city of Berlin, Germany. We extend existing models, by including the effects of various obstructions, higher order interactions, and by introducing an angular gain function for the scatterers. Scatterer locations have been identified and mapped to measured multi-path trajectories using a measurement-based ray tracing method and a subsequent RANSAC algorithm. The developed model is parameterized, and using the measured propagation paths that have been mapped to scatterer locations, model parameters are estimated. The time variant power fading of individual multi-path components is found to be best modeled by a Gamma process with an exponential autocorrelation. The path coherence distance is estimated to be in the range of 0-2 m. The model is also validated against measurement data, showing that the developed model accurately captures the behavior of the measured channel gain, Doppler spread, and delay spread. This is also the case for intersections that have not been used when estimating model parameters.Comment: Submitted to IEEE Transactions on Vehicular Technolog

Scattering regimes for underwater optical wireless communications using Monte Carlo simulation

Optical wireless communications has shown tremendous potential for underwater applications as it can provide higher bandwidth and better security compared to acoustic technologies. In this paper,  an investigation on scattering regimes for underwater links using Monte Carlo simulation has been presented.While the focus of this paper is on diffuse links, the simulation results of collimated links is also provided for comparison purpose. Three types of water namely clear, coastal and turbid water are being used in the simulation. It is shown that the effect of scattering on the path loss cannot be accurately modeled by the existing channel model; ie. Beers-Lambert (BL) law.  It has been shown that  the distance at which the unscattered light drops to zero can be used to estimate the transition point for the scattering regimes in case of diffuse links. The transition point for diffuse links in coastal water and turbid water can be estimated to be around 22 m and 4 m respectively. Further analysis on the scattering order probability at different scattering regimes illustrates how scattering is affected by beam size, water turbidity and distance. From the frequency response plot, it is estimated that the bandwidth of several order of GHz can be achieved when the links are operating in the minimal scattering region and will reduce to several hundreds of MHz when the link is operating in multiple scattering region

Deep space communication and navigation study. Volume 1 - Summary

Comparison of alternative means for high data rate communication from deep space probes, and deep space navigation by orbiting spacecraf

Comparison of Radio Frequency and Visible Light Propagation Channels for Vehicular Communications

Recent research has shown that both radio and visible light waves can be used to enable communications in highly dynamic vehicular environments. However, the roles of these two technologies and how they interact with each other in future vehicular communication systems remain unclear. Understanding the propagation characteristics is an essential step in investigating the benefits and shortcomings of each technology. To this end, we discuss salient properties of radio and visible light propagation channels, including radiation pattern, path loss modeling, noise and interference, and channel time variation. Comparison of these properties provides an important insight that the two communication channels can complement each other’s capabilities in terms of coverage and reliability, thus better satisfying the diverse requirements of future cooperative intelligent transportation systems