3,168 research outputs found
A Survey of Air-to-Ground Propagation Channel Modeling for Unmanned Aerial Vehicles
In recent years, there has been a dramatic increase in the use of unmanned
aerial vehicles (UAVs), particularly for small UAVs, due to their affordable
prices, ease of availability, and ease of operability. Existing and future
applications of UAVs include remote surveillance and monitoring, relief
operations, package delivery, and communication backhaul infrastructure.
Additionally, UAVs are envisioned as an important component of 5G wireless
technology and beyond. The unique application scenarios for UAVs necessitate
accurate air-to-ground (AG) propagation channel models for designing and
evaluating UAV communication links for control/non-payload as well as payload
data transmissions. These AG propagation models have not been investigated in
detail when compared to terrestrial propagation models. In this paper, a
comprehensive survey is provided on available AG channel measurement campaigns,
large and small scale fading channel models, their limitations, and future
research directions for UAV communication scenarios
Indoor wireless communications and applications
Chapter 3 addresses challenges in radio link and system design in indoor scenarios. Given the fact that most human activities take place in indoor environments, the need for supporting ubiquitous indoor data connectivity and location/tracking service becomes even more important than in the previous decades. Specific technical challenges addressed in this section are(i), modelling complex indoor radio channels for effective antenna deployment, (ii), potential of millimeter-wave (mm-wave) radios for supporting higher data rates, and (iii), feasible indoor localisation and tracking techniques, which are summarised in three dedicated sections of this chapter
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
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