Doc.: IEEE 802.15-04/0371r0 Submission July 2004 Andrew Fort & Bart Van Poucke, IMECSlide 1 Project:...

doc.: IEEE 802.15-04/0371r0

Submission

July 2004

Slide 1 Andrew Fort & Bart Van Poucke, IMEC

Project: IEEE 802.15 Working Group for Wireless Personal Area Networks (WPANs)Project: IEEE 802.15 Working Group for Wireless Personal Area Networks (WPANs)

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.

Andrew Fort & Bart Van Poucke, IMECSlide 2

doc.: IEEE 802.15-04/0371r0

Submission

July 2004

BAN UWB Channel Model Update

Andrew Fort

Bart Van Poucke

IMEC, Wireless Research

[email protected]


doc.: IEEE 802.15-04/0371r0

Submission

July 2004

• Experiment setup

• Path loss versus distance

• Path loss versus frequency

• Power delay profile

• Matlab channel model code

Outline


doc.: IEEE 802.15-04/0371r0

Submission

July 2004

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)


doc.: IEEE 802.15-04/0371r0

Submission

July 2004

The measurements were divided up between four areas defined by angle.

Area 1

Area 2Area 2

Area 3Area 3

Area 4Area 1: 0°-50°Area 2: 50°-100°Area 3: 100°-150°Area 4: 150°-180°

• Channel parameters changed as signal travels around the body.


doc.: IEEE 802.15-04/0371r0

Submission

July 2004

Small-scale fading averaged out to extract path loss versus distance.

Measured data

Small-scale fading removed

(area 1 – area 4)Best fit

path loss model

Distance (m)

Pat

h lo

ss (

dB)


doc.: IEEE 802.15-04/0371r0

Submission

July 2004

This path loss model is not the same as the classical path loss model.

Path loss model MSE

1. 32.5

2. 5.4

3. 0.8

)/(log10 0100 ddnPL dBs

)( 0,0, nPL dBdBs

)( 0,0, ddnPL dBdBs

Possible reasons

• Extreme close range• Path loss mechanisms close to body are different


doc.: IEEE 802.15-04/0371r0

Submission

July 2004

Body area channel was not frequency dependent in the 3-5 GHz band

Distance (m)

Pat

h lo

ss (

dB)

To be confirmed…


doc.: IEEE 802.15-04/0371r0

Submission

July 2004

Power Delay Profiles were extracted according to 802.15.4a Guidelines


doc.: IEEE 802.15-04/0371r0

Submission

July 2004

Statistics for each channel tap were tabulated in each area.

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

Area 1

Area 2

Area 3

Area 4


doc.: IEEE 802.15-04/0371r0

Submission

July 2004

Area 2 CDF Area 3 CDF

The model statistics provides a good match to measured data.


doc.: IEEE 802.15-04/0371r0

Submission

July 2004

Preliminary results indicate Body area channel statistics were not the same as

classical indoor statistics.

• Nakagami-m distribution failed the goodness of fit tests in all cases.

• Log-normal distribution was clearly superior.

• Very strong correlation between taps (70-90%)


doc.: IEEE 802.15-04/0371r0

Submission

July 2004

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.


doc.: IEEE 802.15-04/0371r0

Submission

July 2004

We wrote Matlab code to simulate the channel.

Red = Random channels form Matlab

Blue = measured data

Distance (m)

Pat

h lo

ss (

dB)


doc.: IEEE 802.15-04/0371r0

Submission

July 2004

Conclusions

• 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

• This model has been implemented in Matlab.

• Resulting model matches measured results closely.


doc.: IEEE 802.15-04/0371r0

Submission

July 2004

Future Work

• Refine our results by eliminating the influence of boundary reflections and correct any problems with frequency selective material definitions.

• Extend simulation to 2-6 GHz pulses

• Include the impact of the floor.

• Confirm our results with actual measurements

• Measure the path loss at a reference distance close to the antenna.

• Incorporate the influence of surrounding obstacles (if time).

Doc.: IEEE 802.15-04/0371r0 Submission July 2004 Andrew Fort & Bart Van Poucke, IMECSlide 1 Project:...

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