185 research outputs found
Stochastic Geometric Coverage Analysis in mmWave Cellular Networks With Realistic Channel and Antenna Radiation Models
Millimeter-wave (mmWave) bands will play an important role in 5G wireless systems. The system performance can be assessed by using models from stochastic geometry that cater for the directivity in the desired signal transmissions as well as the interference, and by calculating the signal-To-interference-plus-noise ratio ( \mathsf {SINR} ) coverage. Nonetheless, the accuracy of the existing coverage expressions derived through stochastic geometry may be questioned, as it is not clear whether they would capture the impact of the detailed mmWave channel and antenna features. In this paper, we propose an \mathsf {SINR} coverage analysis framework that includes realistic channel model and antenna element radiation patterns. We introduce and estimate two parameters, aligned gain and misaligned gain, associated with the desired signal beam and the interfering signal beam, respectively. The distributions of these gains are used to determine the distribution of the \mathsf {SINR} which is compared with the corresponding \mathsf {SINR} coverage, calculated through the system-level simulations. The results show that both aligned and misaligned gains can be modeled as exponential-logarithmically distributed random variables with the highest accuracy, and can further be approximated as exponentially distributed random variables with reasonable accuracy. These approximations can be used as a tool to evaluate the system-level performance of various 5G connectivity scenarios in the mmWave band.</p
Nuts and Bolts of a Realistic Stochastic Geometric Analysis of mmWave HetNets: Hardware Impairments and Channel Aging
© 2019 IEEE.Motivated by heterogeneous network (HetNet) design in improving coverage and by millimeter-wave (mmWave) transmission offering an abundance of extra spectrum, we present a general analytical framework shedding light on the downlink of realistic mmWave HetNets consisting of K tiers of randomly located base stations. Specifically, we model, by virtue of stochastic geometry tools, the multi-Tier multi-user (MU) multiple-input multiple-output (MIMO) mmWave network degraded by the inevitable residual additive transceiver hardware impairments (RATHIs) and channel aging. Given this setting, we derive the coverage probability and the area spectral efficiency (ASE), and we subsequently evaluate the impact of residual transceiver hardware impairments and channel aging on these metrics. Different path-loss laws for line-of-sight and non-line-of-sight are accounted for the analysis, which are among the distinguishing features of mmWave systems. Among the findings, we show that the RATHIs have a meaningful impact at the high-signal-To-noise-ratio regime, while the transmit additive distortion degrades further than the receive distortion the system performance. Moreover, serving fewer users proves to be preferable, and the more directive the mmWaves are, the higher the ASE becomes.Peer reviewedFinal Accepted Versio
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
MmWave MU-MIMO for Aerial Networks
Millimeter wave offers high bandwidth for air-to-air (A2A) communication. In
this paper, we evaluate the rate performance of a multiuser MIMO (MU-MIMO)
configuration where several aircraft communicate with a central hub. We
consider a hybrid subarray architecture, single path channels, and realistic
atmospheric attenuation effects. We propose a mathematical framework for the
analysis of millimeter wave (mmWave) MU-MIMO networks. Via Monte Carlo
simulation, we demonstrate that mmWave is a promising technology for delivering
gigabit connectivity in next-generation aerial networks.Comment: 5 pages, 4 figures, accepted at ISWCS Special Session 7:
Vehicle-to-Everything (V2X) Communications. Small correction to equation (9)
that I noticed after publication. Code available at:
https://github.com/travisCuvelier/mmWaveAerialNetwork
RIS-Assisted Coverage Enhancement in Millimeter-Wave Cellular Networks
The use of millimeter-wave (mmWave) bandwidth is one key enabler to achieve
the high data rates in the fifth-generation (5G) cellular systems. However,
mmWave signals suffer from significant path loss due to high directivity and
sensitivity to blockages, limiting its adoption within small-scale deployments.
To enhance the coverage of mmWave communication in 5G and beyond, it is
promising to deploy a large number of reconfigurable intelligent surfaces
(RISs) that passively reflect mmWave signals towards desired directions. With
this motivation, in this work we study the coverage of an RIS-assisted
large-scale mmWave cellular network using stochastic geometry, and derive the
peak reflection power expression of an RIS and the downlink
signal-to-interference ratio (SIR) coverage expression in closed forms. These
analytic results clarify the effectiveness of deploying RISs in the mmWave SIR
coverage enhancement, while unveiling the major role of the density ratio
between active base stations (BSs) and passive RISs. Furthermore, the results
show that deploying passive reflectors is as effective as equipping BSs with
more active antennas in the mmWave coverage enhancement. Simulation results
confirm the tightness of the closed form expressions, corroborating our major
findings based on the derived expressions.Comment: Accepted in IEEE ACCESS, Copyright (c) 2015 IEEE. Personal use of
this material is permitted. However, permission to use this material for any
other purposes must be obtained from the IEEE by sending a request to
[email protected]
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