142 research outputs found
Beam Alignment for Millimetre Wave Links with Motion Prediction of Autonomous Vehicles
Intelligent Transportation Systems (ITSs) require ultra-low end-to-end delays
and multi-gigabit-per-second data transmission. Millimetre Waves (mmWaves)
communications can fulfil these requirements. However, the increased mobility
of Connected and Autonomous Vehicles (CAVs), requires frequent beamforming -
thus introducing increased overhead. In this paper, a new beamforming algorithm
is proposed able to achieve overhead-free beamforming training. Leveraging from
the CAVs sensory data, broadcast with Dedicated Short Range Communications
(DSRC) beacons, the position and the motion of a CAV can be estimated and
beamform accordingly. To minimise the position errors, an analysis of the
distinct error components was presented. The network performance is further
enhanced by adapting the antenna beamwidth with respect to the position error.
Our algorithm outperforms the legacy IEEE 802.11ad approach proving it a viable
solution for the future ITS applications and services.Comment: Proc. of IET Colloquium on Antennas, Propagation & RF Technology for
Transport and Autonomous Platforms, to appea
A grid-based coverage analysis of urban mmWave vehicular ad hoc networks
In this letter, a tractable coverage model, specifically designed for urban vehicular ad hoc networks, is presented to aid a better system designer. This is achieved through the use of a model based upon line processes, which simplifies the analysis. It is found, that even in crowded interferer scenarios, mmWave vehicular communications can establish reliable links with an SINR threshold of around 5 dB, with a coverage probability of approximately 0.8 at 50 m separation between a typical transmitter and a typical receiver. These results, and their inference towards the design and deployment of urban vehicular ad-hoc networks, may impact the developments of future vehicle- to-vehicle (V2V) applications and services
Coverage and Connectivity Analysis of Millimeter Wave Vehicular Networks
The next generations of vehicles will require data transmission rates in the
order of terabytes per driving hour, to support advanced automotive services.
This unprecedented amount of data to be exchanged goes beyond the capabilities
of existing communication technologies for vehicular communication and calls
for new solutions. A possible answer to this growing demand for ultra-high
transmission speeds can be found in the millimeter-wave (mmWave) bands which,
however, are subject to high signal attenuation and challenging propagation
characteristics. In particular, mmWave links are typically directional, to
benefit from the resulting beamforming gain, and require precise alignment of
the transmitter and the receiver beams, an operation which may increase the
latency of the communication and lead to deafness due to beam misalignment. In
this paper, we propose a stochastic model for characterizing the beam coverage
and connectivity probability in mmWave automotive networks. The purpose is to
exemplify some of the complex and interesting tradeoffs that have to be
considered when designing solutions for vehicular scenarios based on mmWave
links. The results show that the performance of the automotive nodes in highly
mobile mmWave systems strictly depends on the specific environment in which the
vehicles are deployed, and must account for several automotive-specific
features such as the nodes speed, the beam alignment periodicity, the base
stations density and the antenna geometry.Comment: In press of Elsevier Ad Hoc Network
On the Feasibility of Integrating mmWave and IEEE 802.11p for V2V Communications
Recently, the millimeter wave (mmWave) band has been investigated as a means
to support the foreseen extreme data rate demands of emerging automotive
applications, which go beyond the capabilities of existing technologies for
vehicular communications. However, this potential is hindered by the severe
isotropic path loss and the harsh propagation of high-frequency channels.
Moreover, mmWave signals are typically directional, to benefit from beamforming
gain, and require frequent realignment of the beams to maintain connectivity.
These limitations are particularly challenging when considering
vehicle-to-vehicle (V2V) transmissions, because of the highly mobile nature of
the vehicular scenarios, and pose new challenges for proper vehicular
communication design. In this paper, we conduct simulations to compare the
performance of IEEE 802.11p and the mmWave technology to support V2V
networking, aiming at providing insights on how both technologies can
complement each other to meet the requirements of future automotive services.
The results show that mmWave-based strategies support ultra-high transmission
speeds, and IEEE 802.11p systems have the ability to guarantee reliable and
robust communications.Comment: 7 pages, 5 figures, 2 tables, accepted to the IEEE Connected and
Automated Vehicles Symposium (CAVS
MmWave System for Future ITS:A MAC-layer Approach for V2X Beam Steering
Millimeter Waves (mmWave) systems have the potential of enabling
multi-gigabit-per-second communications in future Intelligent Transportation
Systems (ITSs). Unfortunately, because of the increased vehicular mobility,
they require frequent antenna beam realignments - thus significantly increasing
the in-band Beamforming (BF) overhead. In this paper, we propose Smart
Motion-prediction Beam Alignment (SAMBA), a MAC-layer algorithm that exploits
the information broadcast via DSRC beacons by all vehicles. Based on this
information, overhead-free BF is achieved by estimating the position of the
vehicle and predicting its motion. Moreover, adapting the beamwidth with
respect to the estimated position can further enhance the performance. Our
investigation shows that SAMBA outperforms the IEEE 802.11ad BF strategy,
increasing the data rate by more than twice for sparse vehicle density while
enhancing the network throughput proportionally to the number of vehicles.
Furthermore, SAMBA was proven to be more efficient compared to legacy BF
algorithm under highly dynamic vehicular environments and hence, a viable
solution for future ITS services.Comment: Accepted for publication in IEEE VTC Fall 2017 conference proceeding
Evaluation of IEEE 802.11ad for mmWave V2V Communications
Autonomous vehicles can construct a more accurate perception of their
surrounding environment by exchanging rich sensor data with nearby vehicles.
Such exchange can require larger bandwidths than currently provided by
ITS-G5/DSRC and Cellular V2X. Millimeter wave (mmWave) communications can
provide higher bandwidth and could complement current V2X standards. Recent
studies have started investigating the potential of IEEE 802.11ad to support
high bandwidth vehicular communications. This paper introduces the first
performance evaluation of the IEEE 802.11ad MAC (Medium Access Control) and
beamforming mechanism for mmWave V2V communications. The study highlights
existing opportunities and shortcomings that should guide the development of
mmWave communications for V2V communications.Comment: 6 pages, 5 figures, 1 tabl
- …