Jan. 2007 doc.: 15-07-0547-00-0ban Submission Dries Neirynck - University of Bristol - MVCE Slide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) (WPANs) Submission Title: [Channel measurements and PHY development for wearable devices] Date Submitted: [Jan. 15, 2007 ] Source: [Dries Neirynck] Company: [University of Bristol – Mobile VCE] Address: [Merchant Venturers Building, Woodland Rd, Bristol, BS8 1UB, UK] Voice:[+31 6 48 06 1793], E-Mail:[[email protected], [email protected], [email protected]] Re: [ IEEE 802.15 BAN SG ] Abstract: [Channel measurements, evaluation of current standards and use of MIMO in BAN] Purpose: [To encourage discussion.] Notice: This document has been prepared to assist the IEEE P802.15. 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 P802.15.
Transcript
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Submission Dries Neirynck - University of Bristol - MVCESlide 1
Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [Channel measurements and PHY development for wearable devices]Date Submitted: [Jan. 15, 2007 ]Source: [Dries Neirynck] Company: [University of Bristol – Mobile VCE]Address: [Merchant Venturers Building, Woodland Rd, Bristol, BS8 1UB, UK]Voice:[+31 6 48 06 1793], E-Mail:[[email protected], [email protected], [email protected]]
Re: [ IEEE 802.15 BAN SG ]
Abstract: [Channel measurements, evaluation of current standards and use of MIMO in BAN]
Purpose: [To encourage discussion.]
Notice: This document has been prepared to assist the IEEE P802.15. 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 P802.15.
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Submission Dries Neirynck - University of Bristol - MVCESlide 2
Aim
Contribute to the drafts of the PAR and 5C by presenting the results of channel measurement campaigns into personal and body area
propagation and of 802.15.1 and 15.3 PHY simulations using the recorded channel
data
Performed at the University of Bristol as part of the Mobile VCE Core 3 Programme Fully detailed technical reports on this research are available to
Industrial Members of Mobile VCE.
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Fully detailed technical reports on this research are available to Industrial Members of Mobile VCE:
In cooperation with the UK’s leading comms research Universities
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Submission Dries Neirynck - University of Bristol - MVCESlide 4
BAN versus PAN
In the context of this research defined as:
BAN: two (or more) communicating devices are located on the user’s body
PAN: only one of the communicating devices is carried by the user
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Overview
Does the user have a significant influence on BAN channel characteristics?
How do existing 802.15 standards perform in the measured channels?
What’s the benefit of using multiple antennas in BAN?
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Does the user have a significant influence on BAN channel characteristics?
No indication that user effects were taken into account during design of existing 802.15 standards:
Bluetooth (IEEE 802.15.1): Channel assumptions based on WLAN Attenuation and fading simply based on distance TX-RX
IEEE 802.15.3 Channel model adapted from 802.11 Exponentially decaying, Rayleigh fading tapped delay line
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2 BAN channel measurement campaigns have been carried out
MIMO channel sounder (Medav Rusk BRI)Dual Polar Patch antennas120 MHz @ 5.2 GHzOffice and anechoic chamber
Submission Dries Neirynck - University of Bristol - MVCESlide 8
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User has significant influence on channel characteristics
Body shadowing leads to severe signal attenuation During periods of NLOS, link becomes dependent on multipath
propagation in the environment
User motion leads to huge variation in the channel During periods of motion, coherence time is reduced to tens of
milliseconds
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Measured channel characteristics differ from assumptions during development 802.15.1/3
Bluetooth (IEEE 802.15.1) Channel assumptions based on WLAN measurements attenuation and fading statistics are simply related to distance
between transmitter and receiver link budget: 62 dB attenuation at 10 metres
(observed at much shorter distance in measurements)
IEEE 802.15.3 Exponentially decaying, Rayleigh fading model from 802.11
RMS delay spread of 25 ns should be tolerated 99.9% reliability at 10 metres
No indication that body shadowing is taken into account
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How do existing 802.15 standards perform in the measured channels?
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Bluetooth/IEEE 802.15.1 simulation
Parameters: Baseband only, other layers ideal GFSK modulator (h = 0.28), FEC implemented Demodulation with phase differentiator Packet header info known to receiver Throughput approximated by
Throughput = (1-PER) x max. rate
100 bytes packet length TX power 0 dBm Thermal noise + 20 dB RX noise figure Recorded narrowband channel attenuation 2.4 GHz band
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Bluetooth / IEEE 802.15.3 performs poorly
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IEEE 802.15.3 simulation
Parameters: Baseband only, other layers assumed ideal Modulation and FEC implemented Receiver:
noise-whitening matched filter + DFE(4,3), Viterbi decoder for TC-QAM, Perfect knowledge of channel and packet header info
Throughput approximated as before 100 bytes packet length TX power 10 dBm Thermal noise + 12 dB RX noise figure Recorded narrowband channel attenuation 2.4 GHz band
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IEEE 802.15.3 model can perform well
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What’s the benefit of using multiple antennas in BAN?
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The measurement data from the MIMO channel sounder is used
MIMO channel sounder (Medav Rusk BRI)
Dual Polar Patch antennas 2 antennas per ‘terminal’ 120 MHz @ 5.2 GHz Office and anechoic chamber 30 second routine consisting of
sitting, standing, turning body and touching toes
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Both the use of spatial and polarisation diversity result in considerable capacity increases
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2-by-2 Space-time coding is evaluated based on a scheme proposed by Lindskog
2-by-2 MIMO extension of 802.15.3 based on Lindskog’s adaptation of Alamouti’s scheme for wideband channels
Parameters identical to 802.15.3 simulation Total TX power kept constant Except for measured MIMO channels (5.2 GHz!)
802.15.3TX
Lindskog Encoder
802.15.3RX
MIMO DFE
Decoder
Decoder
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Space-time coding can be used to increase reliability and/or lower TX power
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A 2-by-2 spatial multiplexing extension to 802.15.3 has been investigatedParameters identical to 802.15.3 simulation
Total TX power kept constant (10 dBm) Except for measured MIMO channels (5.2 GHz)
802.15.3 TX
interleaver
TX1
TX2
MIMO DFE-1
deinterleaver802.15.3
RX
RX1
RX2
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Performance in BAN channels
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How can the PHY exploit the presence of multiple antennas in PAN or BAN?
Increase reliability of link with space-time coding 2-by-2 extension based on Lindskog’s scheme evaluated 4-5 dB SNR reduction for similar throughput in BAN channels can be used to extend range or lower TX power
Increase throughput of link with spatial multiplexing 2-by-2 extension achieves predicted doubling of the throughput
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Final Overview
Body shadowing severely attenuates the signalUser motion leads to a very variable channel
This affects the performance of current PAN standards particularly in the case of Bluetooth/802.15.1
Use of multiple antennas should be considered
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