1,557 research outputs found
A predefined channel coefficients library for vehicle-to-vehicle communications
It is noticeable that most of VANETs communications tests are assessed through simulation. In a majority of simulation results, the physical layer is often affected by an apparent lack of realism. Therefore, vehicular channel model has become a critical issue in the field of intelligent transport systems (ITS). To overcome the lack of realism problem, a more robust channel model is needed to reflect the reality. This paper provides an open access, predefined channel coefficients library. The library is based on 2x2 and 4x4 Multiple â Input â Multiple â Output (MIMO) systems in V2V communications, using a spatial channel model extended SCME which will help to reduce the overall simulation time. In addition, it provides a more realistic channel model for V2V communications; considering: over ranges of speeds, distances, multipath signals, sub-path signals, different angle of arrivals, different angle departures, no line of sight and line of sight. An intensive evaluation process has taken place to validate the library and acceptance results are produced. Having an open access predefined library, enables the researcher at relevant communities to test and evaluate several complicated vehicular communications scenarios in a wider manners with less time and efforts
Modeling and Design of Millimeter-Wave Networks for Highway Vehicular Communication
Connected and autonomous vehicles will play a pivotal role in future
Intelligent Transportation Systems (ITSs) and smart cities, in general.
High-speed and low-latency wireless communication links will allow
municipalities to warn vehicles against safety hazards, as well as support
cloud-driving solutions to drastically reduce traffic jams and air pollution.
To achieve these goals, vehicles need to be equipped with a wide range of
sensors generating and exchanging high rate data streams. Recently, millimeter
wave (mmWave) techniques have been introduced as a means of fulfilling such
high data rate requirements. In this paper, we model a highway communication
network and characterize its fundamental link budget metrics. In particular, we
specifically consider a network where vehicles are served by mmWave Base
Stations (BSs) deployed alongside the road. To evaluate our highway network, we
develop a new theoretical model that accounts for a typical scenario where
heavy vehicles (such as buses and lorries) in slow lanes obstruct Line-of-Sight
(LOS) paths of vehicles in fast lanes and, hence, act as blockages. Using tools
from stochastic geometry, we derive approximations for the
Signal-to-Interference-plus-Noise Ratio (SINR) outage probability, as well as
the probability that a user achieves a target communication rate (rate coverage
probability). Our analysis provides new design insights for mmWave highway
communication networks. In considered highway scenarios, we show that reducing
the horizontal beamwidth from to determines a minimal
reduction in the SINR outage probability (namely, at
maximum). Also, unlike bi-dimensional mmWave cellular networks, for small BS
densities (namely, one BS every m) it is still possible to achieve an
SINR outage probability smaller than .Comment: Accepted for publication in IEEE Transactions on Vehicular Technology
-- Connected Vehicles Serie
A Measurement Based Shadow Fading Model for Vehicle-to-Vehicle Network Simulations
The vehicle-to-vehicle (V2V) propagation channel has significant implications
on the design and performance of novel communication protocols for vehicular ad
hoc networks (VANETs). Extensive research efforts have been made to develop V2V
channel models to be implemented in advanced VANET system simulators for
performance evaluation. The impact of shadowing caused by other vehicles has,
however, largely been neglected in most of the models, as well as in the system
simulations. In this paper we present a shadow fading model targeting system
simulations based on real measurements performed in urban and highway
scenarios. The measurement data is separated into three categories,
line-of-sight (LOS), obstructed line-of-sight (OLOS) by vehicles, and non
line-of-sight due to buildings, with the help of video information recorded
during the measurements. It is observed that vehicles obstructing the LOS
induce an additional average attenuation of about 10 dB in the received signal
power. An approach to incorporate the LOS/OLOS model into existing VANET
simulators is also provided. Finally, system level VANET simulation results are
presented, showing the difference between the LOS/OLOS model and a channel
model based on Nakagami-m fading.Comment: 10 pages, 12 figures, submitted to Hindawi International Journal of
Antennas and Propagatio
REVIEW OF WIRELESS MIMO CHANNEL MODELS
The need to increase spectral efficiency has led to the design of multiple antenna systems for both transmit and receive sides otherwise known as MIMO. Channel modeling forms an integral part of this design. Therefore it is very important to investigate and understand existing MIMO channel models. This paper provides a detailed review of existing MIMO channel models, their characteristics, tradeoffs and challenges. As with most models in the scientific and technical fields, open issues in MIMO channel modeling have also been enumerated. http://dx.doi.org/10.4314/njt.v35i2.2
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