1. April 2009
doc.: IEEE /xxxxr0
February 2014
IEEE Regulatory SC DSRC Coexistence Tiger Team V2V Radio Channel Models
Date:
Authors:
Malik Kahn (Cohda Wireless)
Rich Kennedy, Research In Motion

2. April 2009
doc.: IEEE /xxxxr0
February 2014
Abstract
Channel models for vehicle to vehicle communications in the GHz band.
Malik Kahn (Cohda Wireless)
Rich Kennedy, Research In Motion

3. Background Work: References
Ian Tan, Wanbin Tang, Ken Laberteaux, Ahmad Bahai , “Measurement and Analysis of Wireless Channel Impairments in DSRC Vehicular Communications,” Electrical Engineering and Computer Sciences University of California at Berkeley, April 2008.
Paul Alexander, David Haley, Alex Grant , “Cooperative Intelligent Transport Systems: 5.9-GHz Field Trials,” Proceedings of The IEEE Volume:99 , Issue 7, July 2011
Laura Bernado, Thomas Zemen, Fredrik Tufvesson, Andreas F. Molisch, Christoph F. Mecklenbrauker , “Delay and Doppler Spreads of Non-Stationary Vehicular Channels for Safety Relevant Scenarios,” May 2013
Slide 3
Malik Kahn (Cohda Wireless)

4. Merge methodology
All studies were scenario based and at 5.6 to 5.9 GHz. Not all scenarios were in common.
The antenna systems and transmitted power were different across tests
All studies reported RMS Doppler and Delay Spread.
Created a table with Scenario and RMS Delay and Doppler spread, then determined multipath Taps that deliver those statistics
Malik Kahn (Cohda Wireless)

5. Scenario Descriptions
Rural LOS:
Intended primarily as a reference result, this channel applies in very open environments where other vehicles, buildings and large fences are absent.
Urban Approaching LOS:
Two vehicles approaching each other in an Urban setting with buildings nearby.
Malik Kahn (Cohda Wireless)
Slide 5

6. Scenario Descriptions
Street Crossing NLOS:
Two vehicles approaching an Urban blind intersection with other traffic present. Buildings/fences present on all corners.
Highway LOS:
Two cars following each other on Multilane inter-region roadways such as Autobahns. Signs, overpasses, hill- sides and other traffic present.
Highway NLOS:
As for Highway LOS but with occluding trucks present between the vehicles.
Malik Kahn (Cohda Wireless)
Slide 6

7. Channel Model Scenarios
Name
Berkeley
Cohda
Lund
RuralLOS na
Merging Lanes Rural
UrbanApproachingLOS
UrbanLOS
street crossing - suburban without traffic
CrossingNLOS
UrbanNLOS
street crossing -urban single lane
HighwayLOS
HighwayNLOS
general LOS obstruction - highway
RMS Delay Spread (ns)
Berkeley
Cohda
Lund
Merged
Rural LOS 22 49 30
Urban Approaching LOS
320 81 84
100
Street Crossing NLOS
295
125 58
200
Highway LOS
140 62
120
Highway NLOS
398
131 36
250
Doppler Spread (Hz)
Merged (RMS)
782
188
263
353
297
150
298
360
420
180
895
826
380
978
875
236
Malik Kahn (Cohda Wireless)
Slide 7

8. Doppler Spectra
The Delay and Mean Power of the taps is a strong function of the environment whereas the Doppler frequencies can scale with speed stipulated as part of the scenario.
We want asymmetric spectra, and thus the Doppler spectra is specified as half-bath tub. Other options are a uniform offset Classic Bathtub.
The key attributes of these Doppler spectra are that they induce a significant bias to the instantaneous Doppler consistent with the constant macro dynamics of the scenario.
For example two cars approaching a blind intersection will tend to compress frequency on the direct path but may stretch frequency on a reflected path of a following truck.
Power
Classic Bath Tub
Pure Doppler
Asymmetric Uniform
Doppler freq
-fd fd
Malik Kahn (Cohda Wireless)
Slide 8

9. Channel Model Values 144km/hr max differential
Tap1
Tap2
Tap3
Units
Power
-14
-17 dB
Delay 83
183 ns
Doppler
492
-295 Hz
Profile
Static
HalfBT
Tap1
Tap2
Tap3
Tap4
Units
Power
-10
-15
-20 dB
Delay
100
167
500 ns
Doppler
689
-492
886 Hz
Profile
Static
HalfBT
Table 5: Rural LOS Parameters
144km/hr max differential
Table 8: Highway LOS Parameters
252 km/hr max differential
Tap1
Tap2
Tap3
Tap4
Units
Power -8
-10
-15 dB
Delay
117
183
333 ns
Doppler
236
-157
492 Hz
Profile
Static
HalfBT
Tap1
Tap2
Tap3
Tap4
Units
Power -2 -5 -7 dB
Delay
200
433
700 ns
Doppler
689
-492
886 Hz
Profile
Static
HalfBT
Table 6: Urban Approaching LOS Parameters
Table 9: Highway NLOS Parameters
252 km/hr max differential
119km/hr max differential
Tap1
Tap2
Tap3
Tap4
Units
Power -3 -5
-10 dB
Delay
267
400
533 ns
Doppler
295
-98
591 Hz
Profile
Static
HalfBT
Table 7: Crossing NLOS Parameters
126km/hr max differential
Malik Kahn (Cohda Wireless)

10. Channel Model Values
For each of the five scenarios modelled, we show the relevance of these delays and Doppler's in terms of path length difference (in meters) and relative path speed (in m/s.
Last column shows the maximum speed difference between the taps.
Name
RMS Spread
Tap 2
Tap 3
Tap 4
Unit
Doppler Spread km/hr
Rural LOS
29.2 25 55 m
102.8
-15
m/s
144
Urban LOS
49.4 35
100
58.2 12 -8
119
Urban NLOS
287.7 80
120
160
167.2 15 -5 30
126
Highway LOS
31.6 50
150
154.5
-25 45
252
Highway NLOS
371.0 60
130
210
439.4
Malik Kahn (Cohda Wireless)

11. Further Comments & QAs
The specified Doppler spectrum is Half bath tub. The Doppler of each tap changes with time and visits the extreme value (listed in the tables) with highest likelihood. It follows that the worst case instantaneous Doppler scenario could be obtained by using pure Doppler taps.
Another point to note is that because these channel models were derived from the RMS Delay and Doppler spread there is no residual group Doppler or Delay remaining in the channel models. We do not view this as a problem from the device testing point of view. As both group delay and Doppler (frequency) are removed by receivers.
Malik Kahn (Cohda Wireless)
Slide 11