taimoor abbas volvo car corporations taimoor.abbas@volvocars · 2018. 6. 12. · volvo car...

V2x wireless channel modeling for connected carsTaimoor Abbas Volvo Car [email protected]

mailto:[email protected]

V2X Terminology

6/12/2018 2SUMMER SCHOOL ON 5G V2X COMMUNICATIONS - [email protected]

V2NV2I

V2V

P2N

V2P

P2I

I2N

Background

Wireless channel

6/12/2018 SUMMER SCHOOL ON 5G V2X COMMUNICATIONS - [email protected] 3

Transmitantenna

Receiverantenna

Propagation

channel Radio

channel

Background

The wireless channel is a medium used to transmit data wirelessly from the transmitter to the

receiver antenna.

Wireless channel


Background

Why do we need wireless channel modeling?

Ideally, modeling a channel means to calculate or estimate all the processing, due to the physical

environment, effecting a signal from the transmitter to the receiver.

How wireless channel is modeled?

Wireless channel is modeled analytically with the help of simulations or empirically by real world

measurements.

Where it is used?

For the wireless system design, it is used for link-level or system simulations as well as to test the

hardware especially where control and repeatability is required. It can also be used to bench mark

multiple hardware with standard settings.

The major benefits are?

Easy to use, allow better control and repeatability, cost effective and could be scaled

Propagation mechanism

5

Backgroundir

t

1

2

Reflection and

transmissionDiffraction

Scattering WaveguidingLine-of-sight (LOS) component

Multipath components

Typical communication scenario

Propagation mechanism (cont.)


Background

dARX

If we assume the TX/RX antennas to be isotropic being in free space,

2

4RX TXP P

d

=

( )2

4

=

ddL free

Path loss

Small scale fadingLarge scale fading

V2V vs v2i


V2X Channel

Doppler shift for v2v


Key Differences in V2V Channel Modeling


V2X Channel

Wr

Wt

dr, Truck

dt

g1g2, Truckg2, XC90

dr, XC90

Truck Blue

S60

XC90 Black

g2, XC90

LOS: Line-Of-Sight OLOS: Obstructed Line-Of-Sight

NLOS: Non Line-Of-Sight Multilink

V2X Channel Measurements


Modeling

Channel Sounder


Modeling

Measurement based modeling

6/12/2018SUMMER SCHOOL ON 5G V2X COMMUNICATIONS - [email protected] 12

1

2 3

4

Note:

• Measurement tool always has certain

limitations

• It is necessary to keep those limitations

in mind when establishing models

based on the measurements

• For a channel model to be independent

of object, it has to be double directional

and antennas need to be calibrated so

that the response could be subtracted

later on

Measurement campaign step by step


Antenna

calibration

Channel

sounder

mounting

Conduction

measure-

ments



Antenna

calibration

Channel

sounder

mounting

Conduction

measure-

ments

General observations – v2v measurements


Time-delay characteristics:

0 100 200 300 400Propagation distance [m]

Pow

er

t = 0 s


Pow

er

t = 0.2 s


Pow

er

t = 0.4 s


Pow

er

t = 0.6 s


Pow

er

t = 0.8 s


Pow

er

t = 1 s


Pow

er

t = 1.3 s


Pow

er

t = 1.5 s


Pow

er

t = 1.7 s


Pow

er

t = 1.9 s


Pow

er

t = 2.1 s


Pow

er

t = 2.3 s


Pow

er

t = 2.5 s


Pow

er

t = 2.8 s


Pow

er

t = 3 s


Pow

er

t = 3.2 s


Pow

er

t = 3.4 s


Pow

er

t = 3.6 s


Pow

er

t = 3.8 s


Pow

er

t = 4.1 s


Pow

er

t = 4.3 s


Pow

er

t = 4.5 s


Pow

er

t = 4.7 s


Pow

er

t = 4.9 s


Pow

er

t = 5.1 s


Pow

er

t = 5.3 s


Pow

er

t = 5.6 sRX

TX


Pow

er

t = 5.8 s


Pow

er

t = 6 s


Pow

er

t = 6.2 sLOS


Pow

er

t = 6.4 s


Pow

er

t = 6.6 s


Pow

er

t = 6.9 s


Pow

er

t = 7.1 s


Pow

er

t = 7.3 s


Pow

er

t = 7.5 s


Pow

er

t = 7.7 s


Pow

er

t = 7.9 s


Pow

er

t = 8.1 sDiscrete comp.

Diffuse comp.

Other vehicles

Houses, road signs etc.

• Rapidly varying channel

• Discrete components carry significant energy and change delay bin with time

• Diffuse components following LOS

General observations – v2v measurements


-1500-1000

-5000

5001000

1500

0

100

200

300

400

500

-90

-80

-70

-60

-50

Doppler frequency [Hz]Delay [ns]

Po

wer

[d

B]

-1500-1000

-5000

5001000

1500

0

100

200

300

400

500

-90

-80

-70

-60

-50


Po

wer

[d

B]

-1500-1000

-5000

5001000

1500

0

100

200

300

400

500

-90

-80

-70

-60

-50


Po

wer

[d

B]

-1500-1000

-5000

5001000

1500

0

100

200

300

400

500

-90

-80

-70

-60

-50


Po

wer

[d

B]

-1500-1000

-5000

5001000

1500

0

100

200

300

400

500

-90

-80

-70

-60

-50


Po

wer

[d

B]

-1500-1000

-5000

5001000

1500

0

100

200

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500

-90

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-60

-50


Po

wer

[d

B]

-1500-1000

-5000

5001000

1500

0

100

200

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500

-90

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-50


Po

wer

[d

B]

-1500-1000

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5001000

1500

0

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200

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-90

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-50


Po

wer

[d

B]

-1500-1000

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5001000

1500

0

100

200

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500

-90

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-50


Po

wer

[d

B]

-1500-1000

-5000

5001000

1500

0

100

200

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400

500

-90

-80

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-60

-50


Po

wer

[d

B]

-1500-1000

-5000

5001000

1500

0

100

200

300

400

500

-90

-80

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-60

-50


Po

wer

[d

B]

-1500-1000

-5000

5001000

1500

0

100

200

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-80

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-50


Po

wer

[d

B]

-1500-1000

-5000

5001000

1500

0

100

200

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500

-90

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-50


Po

wer

[d

B]

-1500-1000

-5000

5001000

1500

0

100

200

300

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500

-90

-80

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Po

wer

[d

B]

LOS

Discrete components

Diffuse components

-1500-1000

-5000

5001000

1500

0

100

200

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400

500

-90

-80

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-60

-50


Po

wer

[d

B]

-1500-1000

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5001000

1500

0

100

200

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500

-90

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-50


Po

wer

[d

B]

-1500-1000

-5000

5001000

1500

0

100

200

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500

-90

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-50


Po

wer

[d

B]

-1500-1000

-5000

5001000

1500

0

100

200

300

400

500

-90

-80

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-60

-50


Po

wer

[d

B]

-1500-1000

-5000

5001000

1500

0

100

200

300

400

500

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-50


Po

wer

[d

B]

-1500-1000

-5000

5001000

1500

0

100

200

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-50


Po

wer

[d

B]

-1500-1000

-5000

5001000

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0

100

200

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500

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Po

wer

[d

B]

-1500-1000

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5001000

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0

100

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Po

wer

[d

B]

-1500-1000

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5001000

1500

0

100

200

300

400

500

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-80

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-60

-50

Doppler frequency [Hz]

t = 7.4 s

Delay [ns]

Po

wer

[d

B]

Local scattering function:

• Discrete components: small Doppler spread, but can change delay bin rapidly

• Diffuse components: large delay and Doppler spread

• Time-variant Doppler spectrum → Non-stationary conditions

Measurement based modeling


The time during which the localscattering function is ”sufficientlyconstant” is defined as the stationaritytime

Highway, opposite

direction

Highway, same

direction

Urban, same direction

23 ms 1479 ms 1412 ms

A geometry based stochastic model


Diffuse scatterers

Mobile discrete scatterers

Static discrete scatterers

Adding up all components using different antenna patterns → MIMO channels

Dependent on antenna pattern

Deterministic modeling


• Non-measurement based modeling could either

be statistical geometry based of deterministic

• Deterministic approach, such as ray tracing, can

be very realistic but computationally expensive

• Moreover, it requires accurate geometry

• Solve approximation to Maxwell’s equation,

using high-frequency approximation

[Maurer et al. 2004]

Ray tracing example


Measurements vs ray tracing


• Very good agreement in LOS and near LOS regions.

• In NLOS, the ray tracing model underestimates the channel

gain.

• Gap can be reduced by increasing the order of reflection.

• Contribution of third and higher-order specular and non-

specular reflections is missing in the simulator.

Measuremed PDP Simulated PDP (Ray-tracing)

Channel gain

LOSNLOS

• A channel model is selected based on what part of the communication system that is going to be studied.

• For network level simulations, where communication protocols are studied, a statistical model (e.g., Rician, Rayleigh, and Nakagami) is the predominant channel model type to keep computational time down.

• For PHY layer, TDLs and geometry-based stochastic and deterministic channel models are for obvious reasons the preferred channel models.

• So selection of channel model has to be made very carefully as the channel is one of the major performance factors

• To summarize; following is a receipe on the selection and usage of channelmodels.

Channel models for test and simulations


V2X- Channel: Specific considerations


V2X Channel

V2x channel models classification


3GPP TR38.901: V2X-specific Considerations


Summary of parameter to be used


References


• I would like to thank my colleagues from Lund University as some of the work is produced jointly, especially Fredrik Tufvesson, Johan Kåredal and Mikael Nilsson.

• Special thanks to Mate Boban from Huawei, Munich, for sharing information about the activities at 3GPP and for the cooperation under the umbrella of 5GCAR on channel modeling.

Thank you for listening!

acknowledgement


• A. Paier, J. Kåredal, N. Czink, C. Dumard, T. Zemen, F. Tufvesson, A. Molisch, C. F. Mecklenbräuker, ”Characterization of Vehicle-to-Vehicle Radio Channels from Measurements at 5.2GHz,” Wireless Personal Communications, vol. 50, no. 1, pp. 19-29, 2009.

• J. Kåredal, F. Tufvesson, N. Czink, A. Paier, C. Dumard, T. Zemen, C. Mecklenbräuker, A. Molisch, ”A geometry-based stochastic MIMO model for vehicle-to-vehicle communications,” IEEE Transactions on Wireless Communications, vol. 8, no. 7, pp. 3646-3657, 2009.

• A. Molisch, F. Tufvesson, J. Kåredal, C. F. Mecklenbräuker, ”A Survey on Vehicle-to-Vehicle Propagation Channels,” IEEE Wireless Communications, vol. 16, no. 6, pp. 12-22, 2009.

• J. Kåredal, F. Tufvesson, T. Abbas, O. Klemp, A. Paier, L. Bernadó, A. Molisch, ”Radio channel measurements at street intersections for vehicle-to-vehicle applications,” Proc. IEEE Vehicular Technology Conference (VTC2010-spring), Taipei, Taiwan, pp. 1-5, May 16-19, 2010.

• A. Paier, L. Bernadó, J. Kåredal, O. Klemp, A. Kwoczek, ”Overview of vehicle-to-vehicle radio channel measurements for collision avoidance applications,” Proc. IEEE Vehicular Technology Conference (VTC2010-spring), Taipei, Taiwan, pp. 1-5, May 16-19, 2010.

• A. Molisch, F. Tufvesson, J. Kåredal, C. Mecklenbräuker, ”Propagation aspects of vehicle-to-vehicle communications - an overview,” Proc. IEEE Radio and Wirless Symposium (RWS), San Diego, CA, USA, pp. 179-182, Jan. 18-22, 2009.

• J. Kåredal, F. Tufvesson, N. Czink, A. Paier, C. Dumard, T. Zemen, C. Mecklenbräuker, A. Molisch, ”Measurement-based modeling of vehicle-to-vehicle MIMO channels,” Proc. IEEE International Conference on Communications (ICC), Dresden, Germany, June 14-18, 2009.

Selected publications


• A. Paier, T. Zemen, J. Kåredal, N. Czink, C. Dumard, F. Tufvesson, C. Mecklenbräuker, A. Molisch, ”Spatial diversity and spatial correlation evaluation of measured vehicle-to-vehicle radio channels at 5.2 GHz,” Proc. IEEE Digital Signal Processing Workshop/Signal Processing Education Workshop (DSP/SPE), pp. 326-330, Jan 1-4, 2009.

• L. Bernadó, T. Zemen, A. Paier, J. Kåredal, B. Fleury, ”Parametrization of the local scattering function estimator for vehicular-to-vehicular channels,” Proc. IEEE Vehicular Technology Conference (VTC2009-fall), Anchorage, AK, USA, pp. 1-5, Sept. 20-23, 2009.

• A. Paier, T. Zemen, L. Bernado, G. Matz, J. Kåredal, N. Czink, C. Dumard, F. Tufvesson, A. Molisch, C. Mecklenbräuker, ”Non-WSSUS vehicular channel characterization in highway and urban scenarios at 5.2 GHz using the local scattering function,” Proc. International Workshop on Smart Antennas (WSA), pp. 9-15, 2008.

• L. Bernadó, T. Zemen, A. Paier, G. Matz, J. Kåredal, N. Czink, C. Dumard, F. Tufvesson, M. Hagenauer, A. Molisch, C. F. Mecklenbräuker, ”Non-WSSUS Vehicular Channel Characterization at 5.2 GHz - Spectral Divergence and Time-Variant Coherence Parameters,” Proc. URSI General Assembly, 2008.

• A. Paier, J. Kåredal, N. Czink, H. Hofstetter, C. Dumard, T. Zemen, F. Tufvesson, C. Mecklenbräuker, A. Molisch, ”First results from car-to-car and car-to-infrastructure radio channel measurements at 5.2GHz,” Proc. IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), Athens, Greece, pp. 1-5, Sept. 3-7, 2007.

• A. Paier, J. Kåredal, N. Czink, H. Hofstetter, C. Dumard, T. Zemen, F. Tufvesson, A. Molisch, C. Mecklenbräuker, ”Car-to-car radio channel measurements at 5 GHz: Pathloss, power-delay profile, and delay-Doppler spectrum,” Proc. IEEE International Symposium on Wireless Communication Systems (ISWCS), Trondheim, Norway, pp. 224-228, Oct. 17-19, 2007.



• C. Mecklenbräuker, A. Molisch, J. Karedal, F. Tufvesson, A. Paier, L. Bernadó, T. Zemen, O. Klemp, N. Czink: Vehicular channel characterization and its implications for wireless system design and performance, Proceedings of the IEEE, Vol. 99, No. 7, pp. 1189-1212, 2011.

• T. Abbas, J. Karedal, F. Tufvesson, A. Paier, L. Bernadó, A. Molisch: Directional Analysis of Vehicle-to-Vehicle Propagation Channels, IEEE Vehicular Technology Conference, IEEE 73rd Vehicular Technology Conference 2011-spring, Budapest, Hungary, 2011-05-15/2011-05-18.

• T. Abbas, and F. Tufvesson: Line-of-Sight Obstruction Analysis for Vehicle-to-Vehicle Network Simulations in a Two Lane Highway Scenario, Hindawi International Journal of Antennas and Propagation, Special Issue on Radio Wave Propagation and Wireless Channel Modeling (In press)

• T. Abbas, L. Bernadó, A. Thiel, C. F. Mecklenbräuker, and F. Tufvesson: Radio Channel Properties for Vehicular Communication: Merging Lanes Versus Urban Intersections, IEEE Vehicular Technology Magazine, December, 2013 (Invited paper)

• T. Abbas, J. Kåredal, and F. Tufvesson: Measurement-Based Analysis: The Effect of Complementary Antennas and Diversity on Vehicle-to-Vehicle Communication, IEEE Antennas and Wireless Propagation Letters, 2012.

• T. Abbas, J. Nuckelt, T. Kürner, T. Zemen, C. Mecklenbräuker, and F. Tufvesson: Simulation and Measurement Based Vehicle-to-Vehicle Channel Characterization: Accuracy and Constraint Analysis (Accepted with major revision, 2014 to IEEE Transactions on Antennas and Propagations).

• T. Abbas: Measurement Based Channel Characterization and Modeling for Vehicle-to-Vehicle Communications, Series of licentiate and doctoral dissertations, ISSN 1654-790X (No. 58), Department of Electrical and Information Technology, Lund University, Sweden, 2014.



• M. Boban, J. Barros, and O. Tonguz, “Geometry-based vehicle-to-vehicle channel modeling for large-scale simulation,” IEEE Transactions on Vehicular Technology, Vol. 63, No. 9, November 2014

• Mikael G. Nilsson et. al “On Multilink Shadowing Effects in Measured V2V Channels on Highway”, 2016

• Mikael G. Nilsson et. al “A Measurement-Based Multilink Shadowing Model for V2V Network simulations of Highway Scenarios”, 2017

• Mikael G. Nilsson et. al “A Path Loss and Shadowing Model for Multilink Vehicle-to-Vehicle Channels in Urban Intersections”, 2018

• Mate Boban et. Al “Multi-band Spatio-Temporal Characterization of a V2V Environment Under Blockage“, 2018



taimoor abbas volvo car corporations taimoor.abbas@volvocars · 2018. 6. 12. · volvo car...

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