Transcript 15-04-0371-00-004a-ban-uwb-channel-model-update.ppt

Project: IEEE 802.15 Working Group for Wireless Personal Area Networks (WPANs)
July 2004
doc.: IEEE 802.15-04/0371r0
Submission Title: [Body Area Network UWB channel modeling update]
Date Submitted: [14July2004]
Source: [Andrew Fort and Bart Van Poucke] Company [IMEC]
Address [Kapeldreef 75, Leuven, Belgium 3001]
Voice:[+32(0)16 28 12 11], FAX: [+32(0)16 22 94 00], E-Mail:[[email protected]]
Re: [Channel model proposal]
Abstract: [Update on channel model for communication around the body]
Purpose: [Contribute to low power air-interface definition for body area applications]
Notice: This document has been prepared to assist the IEEE 802.15. It is offered as a basis for
discussion and is not binding on the contributing individual(s) or organization(s). The material in this
document is subject to change in form and content after further study. The contributor(s) reserve(s) the right
to add, amend or withdraw material contained herein.
Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE
and may be made publicly available by 802.15.
Submission
Slide 1
Andrew Fort & Bart Van Poucke, IMEC
July 2004
doc.: IEEE 802.15-04/0371r0
BAN UWB Channel Model Update
Andrew Fort
Bart Van Poucke
IMEC, Wireless Research
[email protected]
Submission
Slide 2
Andrew Fort & Bart Van Poucke, IMEC
July 2004
doc.: IEEE 802.15-04/0371r0
Outline
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Experiment setup
•
Path loss versus distance
•
Path loss versus frequency
•
Power delay profile
•
Matlab channel model code
Submission
Slide 3
Andrew Fort & Bart Van Poucke, IMEC
July 2004
doc.: IEEE 802.15-04/0371r0
Model is Based on Over 500
Measurements Taken Around the Torso
9 Simulations were made along the height of the torso.
Each simulation measured several positions around the torso.
Measurement were spaced at least 4 cm or approximately ½ the
center frequency wavelength.
 UWB pulse: 3-5 GHz Gaussian Pulse (10 dB bandwidth)



Submission
Slide 4
Andrew Fort & Bart Van Poucke, IMEC
July 2004
doc.: IEEE 802.15-04/0371r0
The measurements were divided up
between four areas defined by angle.
Area 4
Area 3
Area 3
Area 2
Area 2
Area 1: 0°-50°
Area 2: 50°-100°
Area 3: 100°-150°
Area 4: 150°-180°
Area 1
• Channel parameters changed as signal travels
around the body.
Submission
Slide 5
Andrew Fort & Bart Van Poucke, IMEC
July 2004
doc.: IEEE 802.15-04/0371r0
Small-scale fading averaged out to
extract path loss versus distance.
Path loss (dB)
Measured data
Best fit
path loss
model
Small-scale
fading removed
(area 1 – area 4)
Distance (m)
Submission
Slide 6
Andrew Fort & Bart Van Poucke, IMEC
July 2004
doc.: IEEE 802.15-04/0371r0
This path loss model is not the same
as the classical path loss model.
Path loss model
MSE
1.
Ls  P0 dB  10n log 10 (d / d 0 )
32.5
2.
Ls ,dB  P0,dB  n(   0 )
5.4
3.
Ls ,dB  P0,dB  n(d  d 0 )
0.8
Possible reasons
• Extreme close range
• Path loss mechanisms close to body are different
Submission
Slide 7
Andrew Fort & Bart Van Poucke, IMEC
July 2004
doc.: IEEE 802.15-04/0371r0
Path loss (dB)
Body area channel was not frequency
dependent in the 3-5 GHz band
To be confirmed…
Distance (m)
Submission
Slide 8
Andrew Fort & Bart Van Poucke, IMEC
July 2004
doc.: IEEE 802.15-04/0371r0
Power Delay Profiles were extracted
according to 802.15.4a Guidelines
Submission
Slide 9
Andrew Fort & Bart Van Poucke, IMEC
July 2004
doc.: IEEE 802.15-04/0371r0
Statistics for each channel tap were
tabulated in each area.
Area 1
Area 2
Area 3
Area 4
Submission
Tap
dB
dB
K-S
2

1
5.32
7.33
Pass
Inconclusive
1
Tap
dB
dB
K-S
2

1
14.47
12.73
Pass
Pass
1
2
26.54
12.00
Pass
Pass
0.87
Tap
dB
dB
K-S
2

1
25.87
15.97
Pass
Fail
1
2
33.50
13.99
Pass
Pass
0.91
3
42.87
11.15
Pass
Pass
0.76
4
47.10
10.93
Pass
Pass
0.70
5
58.56
11.46
Pass
Pass
0.85
Tap
dB
dB
K-S
2

1
21.33
13.53
Pass
Fail
1
2
26.71
12.18
Pass
Pass
0.89
3
30.96
13.10
Pass
Pass
0.78
4
35.11
9.73
Pass
Pass
0.78
5
51.58
11.35
Pass
Pass
0.86
Slide 10
Andrew Fort & Bart Van Poucke, IMEC
July 2004
doc.: IEEE 802.15-04/0371r0
The model statistics provides a good
match to measured data.
Area 2 CDF
Submission
Area 3 CDF
Slide 11
Andrew Fort & Bart Van Poucke, IMEC
July 2004
doc.: IEEE 802.15-04/0371r0
Preliminary results indicate Body area
channel statistics were not the same as
classical indoor statistics.
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Nakagami-m distribution failed the goodness of fit tests in all cases.
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Log-normal distribution was clearly superior.
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Very strong correlation between taps (70-90%)
Submission
Slide 12
Andrew Fort & Bart Van Poucke, IMEC
July 2004
doc.: IEEE 802.15-04/0371r0
Our parameters and conclusions may
change before August.
Problems we have identified and will rectify soon:
• The boundary conditions were not well adjusted: some reflections
off of the edge of our simulation environment could have influenced
measurements taken on the back.
• We encountered some errors when simulating frequency selective
materials.
Submission
Slide 13
Andrew Fort & Bart Van Poucke, IMEC
July 2004
doc.: IEEE 802.15-04/0371r0
Path loss (dB)
We wrote Matlab code
to simulate the channel.
Red = Random channels form Matlab
Blue = measured data
Distance (m)
Submission
Slide 14
Andrew Fort & Bart Van Poucke, IMEC
July 2004
doc.: IEEE 802.15-04/0371r0
Conclusions
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We have developed an UWB channel model for 3-5 GHz band including the following:
–
–
–
–
Path loss versus distance
Path loss versus frequency
Small scale fading statistics
Power delay profile
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This model has been implemented in Matlab.
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Resulting model matches measured results closely.
Submission
Slide 15
Andrew Fort & Bart Van Poucke, IMEC
July 2004
doc.: IEEE 802.15-04/0371r0
Future Work
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Refine our results by eliminating the influence of boundary reflections and correct any
problems with frequency selective material definitions.
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Extend simulation to 2-6 GHz pulses
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Include the impact of the floor.
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Confirm our results with actual measurements
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Measure the path loss at a reference distance close to the antenna.
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Incorporate the influence of surrounding obstacles (if time).
Submission
Slide 16
Andrew Fort & Bart Van Poucke, IMEC