1,301 research outputs found
3-D Statistical Channel Model for Millimeter-Wave Outdoor Mobile Broadband Communications
This paper presents an omnidirectional spatial and temporal 3-dimensional
statistical channel model for 28 GHz dense urban non-line of sight
environments. The channel model is developed from 28 GHz ultrawideband
propagation measurements obtained with a 400 megachips per second broadband
sliding correlator channel sounder and highly directional, steerable horn
antennas in New York City. A 3GPP-like statistical channel model that is easy
to implement in software or hardware is developed from measured power delay
profiles and a synthesized method for providing absolute propagation delays
recovered from 3-D ray-tracing, as well as measured angle of departure and
angle of arrival power spectra. The extracted statistics are used to implement
a MATLAB-based statistical simulator that generates 3-D millimeter-wave
temporal and spatial channel coefficients that reproduce realistic impulse
responses of measured urban channels. The methods and model presented here can
be used for millimeter-wave system-wide simulations, and air interface design
and capacity analyses.Comment: 7 pages, 6 figures, ICC 2015 (London, UK, to appear
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
Investigation of Prediction Accuracy, Sensitivity, and Parameter Stability of Large-Scale Propagation Path Loss Models for 5G Wireless Communications
This paper compares three candidate large-scale propagation path loss models
for use over the entire microwave and millimeter-wave (mmWave) radio spectrum:
the alpha-beta-gamma (ABG) model, the close-in (CI) free space reference
distance model, and the CI model with a frequency-weighted path loss exponent
(CIF). Each of these models have been recently studied for use in standards
bodies such as 3GPP, and for use in the design of fifth generation (5G)
wireless systems in urban macrocell, urban microcell, and indoor office and
shopping mall scenarios. Here we compare the accuracy and sensitivity of these
models using measured data from 30 propagation measurement datasets from 2 GHz
to 73 GHz over distances ranging from 4 m to 1238 m. A series of sensitivity
analyses of the three models show that the physically-based two-parameter CI
model and three-parameter CIF model offer computational simplicity, have very
similar goodness of fit (i.e., the shadow fading standard deviation), exhibit
more stable model parameter behavior across frequencies and distances, and
yield smaller prediction error in sensitivity testing across distances and
frequencies, when compared to the four-parameter ABG model. Results show the CI
model with a 1 m close-in reference distance is suitable for outdoor
environments, while the CIF model is more appropriate for indoor modeling. The
CI and CIF models are easily implemented in existing 3GPP models by making a
very subtle modification -- by replacing a floating non-physically based
constant with a frequency-dependent constant that represents free space path
loss in the first meter of propagation.Comment: Open access available at:
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=743465
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