THALES proposal for IEEE 802.15.4a

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Project IEEE P802.15 Working Group for Wireless
Personal Area Networks (WPANs) Submission Title
THALES UWB Impulse Radio System Date
Submitted January 3rd, 2005 Source (1)
Serge HETHUIN, Isabelle BUCAILLE, Arnaud
TONNERRE, Fabrice LEGRAND, (2)
Dr. Jurianto JOE Company (1) THALES
Communications France, (2) CELLONICS Address
(1) 146 Boulevard de VALMY, Colombes 92704
FRANCE (2) 20 Science Park Road
117674 SINGAPORE Voice(1) 33 (0)1 46 13 24
44, (2) (65) 68 74 90 10 E-Mail(1)
serge.hethuin_at_fr.thalesgroup.com, (2)
juriantoj_at_cellonics.com Re Response to Call
for Proposals Abstract This document proposes
THALES Communicationss PHY proposal for the IEEE
802.15.4 alternate PHY standard Purpose Proposa
l for the IEEE802.15.4a standard 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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THALES Communications, CELLONICS Proposal for
IEEE 802.15.4a
UWB Impulse Radio

• Serge HETHUIN (THALES Communications)
• Dr. Jurianto JOE (CELLONICS)

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Contents

• Proposal overview
• System description
• Location Awareness

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Proposal overview
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UWB Impulse Radio System
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UWB Pulse and Spectrum
Objective Pulse with 500MHz BW
5.1-5.6GHz sub-band is turned off. (enhance
coexistence)
FCC Mask

• Example
• 4ns Gaussian Pulse
• 1st Frequency Center
• 3.35GHz
• 10dB BW 500MHz
• Tx Power (average)
• - 14.3dBm

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Proposal main features

• Low Power Consumption
• Very Simple Architecture
• One Bit ADC
• Low Cost
• CMOS Implementation
• High Location Accuracy
• Narrow Pulse ? 75cm in 70m region (AWGN)
• Scalability
• by using
• compression gain
• different PRFs
• ? 350kbps _at_70m, , 25Mbps _at_10m

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System Description
- PHY layer characteristics - Topologies and
access protocol - Solution maturity
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PHY layer Parameters
4ns Gaussian Pulse Data Rate depends on ?
compression gain ( Spread Factor) ? PRF
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PHY layer Link Budget
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PHY layer Transceiver architecture
MAC
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PHY layer Modulation Spreading
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PHY layer Synchronization

• Synchronization in 2 steps
• Pulse Edge detection
• Sequence Correlation using Digital Matched
  Filter

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Topologies and access protocol
Multiple Access CDMA (inter-piconet)
802.15.4 (intra-piconet)
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Topologies and localization
Node to be located
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Frame format
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Technical Feasibility and Maturity
TRANSMITTER
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Technical Feasibility and Maturity
Square-law Detector
DATA
FPGA
RECEIVER
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Prototypes characterization with a Test Bed

• Communication Analyzer
• Generates PN Sequence Binary data to feed into
  FPGA TX.
• FPGA TX
• Encodes the binary data into OOK BB pulse and
  feeds it into the UWB Pulse Generator.
• Variable Attenuator
• Allows S/N to be varied.
• UWB receiver
• Converts the UWB signal to OOK BB pulse and feeds
  into FPGA RX.
• FPGA RX
• Decodes the pulses into binary data and feeds
  them back to the communication analyzer.
• Communication analyzer
• Internally compares the recovered sequence with
  the generated sequence.

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Results of transceivers testing

• Consumption
• ? Tx15 mA, Rx 25 mA
• ? Comparable to Tx and Rx power consumption in
  802.15.4
• Data rate and range
• 25 Mbps 15m (_at_ RF power-14dBm)
• 250 kbps 150m
• Location Accuracy
• 75cm with a range up to 70m

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Location Awareness
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Location Awareness

• Multilateration for Location Awareness
• Two modes with at least 3 known-position nodes
• ? Two-way ranging method
• (RTT based)
• ? One-way ranging method
• (TOA based)
• High Location Accuracy
• ? AWGN 75cm _at_ 70m Range

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Mode 1 Two-Way Ranging method (TWR)

• Advantages
• ? Each measurement can be done sequentially
• Possible extension to the case without anchors
• Synchronization
• No need of fine Sync.
• Accuracy
• ? Error is the combination of the detection in
  the two nodes

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TWR System Deployment
No need of Synchronization by a node Asynchronous
Anchors
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TWR Based Measurement
Interrogation from anchor 1
Answer received in anchor 1
Answer from anchor 1
RTT(d1) information sent to the server
Anchor 1
Node to be located
RTT(d1)
time
RTT(d2) information sent to the server
Anchor 2
Node to be located
time
RTT(d2)
RTT(d3) information sent to the server
Anchor 3
Node to be located
time
RTT(d3)
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Mode 2 One-Way Ranging method (OWR)

• Advantage
• Can relax the RFD specifications
• Transmit Only
• No need of detection in the node to be located
• Accuracy
• Accuracy depends only on the clock of the FFD
• Synchronization
• ? More touchy than using RTT/TWR

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OWR System Deployment
Synchronization by a node
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OWR Based Measurement
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On-going tasks

• Multipath study
• Modulation improvements
• FDMA extension
• Localization experiments
• In free space, rural and urban environments
• Comparison with MATLAB simulations
• Coherent receivers
• Comparison with non-coherent receivers

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Conclusion

• UWB IR main features
• BW500MHz
• 4ns Gaussian Pulse with PRF of 25MHz/2.5MHz
• OOK modulation
• ? Very low complexity and Very low cost
• ? Scalable (25Mbps at 10m, , 350kbps at 70m, )
• Location Awareness
• Two possible modes TWR or OWR
• 75cm in 70m region (AWGN)