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

• UWB IR proposal
• System description
• Location Awareness
• Conclusion

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UWB Impulse Radio System(UWB IR)
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UWB Pulse and Spectrum
Objective Impulse Pulse with 500MHz BW

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

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UWB IR main features

• Low Power Consumption
• Very Simple Architecture
• One Bit ADC (for the simplest version)
• Low Cost
• CMOS Implementation
• 500MHz BW leading to many economic
  implementations
• High Location Accuracy
• Narrow Pulse (4ns) ? 75cm in 70m region (AWGN)
• Scalability
• by using
• compression gain (coded sequence)
• different PRFs
• ? 350kbps _at_70m, , 25Mbps _at_10m

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System Description

1. Parameters of the PHY layer
2. Topologies and access protocol
3. Solution maturity
4. Options and eventual extensions

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PHY layer Parameters
4ns Gaussian Pulse Data Rate depends on ?
compression gain ( Spread Factor) ? PRF
Data Rate PRF (MHz) Modulation Compression gain (Spread Factor) Pulses / bit
25 Mbps 25 OOK 1 1
396 kbps 25 OOK 63 63
2.5 Mbps 2.5 OOK 1 1
357 kbps 2.5 OOK 7 7
166 kbps 2.5 OOK 15 15
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PHY layer Link Budget
Parameters Value 350kbps 70m Value 25Mbps 10m Units
Center Frequency 3350 3350 MHz
Transmit Power (4ns Gaussian Pulse) -14.3 -14.3 dBm
PRF 2.5 25 MHz
Spread Factor 7 1
Data Rate 357 25000 kbps
Path Loss at 1m 44 44 dB
Distance 70 10 m
Decay coefficient 2.0 2.0 -
Additional Path Loss at 70m,10m 37.0 20.0 dB
Implementation Loss 2.0 2.0 dB
Antenna gain 0.0 0.0 dBi
Required Eb/N0 _at_BER0.001 10.0 10.0 dB
Noise Power Density -174 -174 dBm
Receiver Total NF 7.0 7.0 dB
Margin 4.9 4.9 dB
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PHY layer Transceiver architecture
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PHY layer Modulation Spreading
Specifications
RF Frequency 3350250MHz (10dB BW)
Modulation OOK
Spreading Coded Sequence Kasami (15, 63) and Gold (7)
Despreading Digital Matched Filter
PRF 25MHz, 2.5MHz
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PHY layer Synchronization

• Synchronization
• 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
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Inter-Piconet Multiple Access

• CDMA Inter-Piconet with one sequence / Piconet

Intercorrelation between sequences 1 and 2
KASAMI 1 sequence
KASAMI 2 sequence
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Frame format
2
1
0/4/8
2
n
Bytes
Data Payload
Frame Control
MAC Sublayer
Seq.
Address
CRC
4
1
1
Bytes
PHY Layer
Frame Length
Preamble
SFD
MPDU
PPDU
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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 and provides the BER on
  screen.

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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 gt150m
• High Location Accuracy
• 75cm with a range up to 70m

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Options and eventual extensions

• Multipath study
• ? On-going study (results in March 2005)
• Modulation improvements
• DBPSK in complement of OOK
• Localization improvements
• Processing to deal with Indoor environments
  (buildings, underground park, )
• Multiband extension (MBSC)
• Additional feature to discriminate the different
  piconets
• Additional capability for data rate increase
• Additional function to mitigate propagation
  problems

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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
• (Round Trip Time measurement based)
• One-way ranging method with one additional node
  for synchronization
• (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
System Configuration for 2D location measurements
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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)

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

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OWR System Deployment
Synchronization by a node
System Configuration for 2D location measurements
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TOA Based Measuring
Synchronization by a node
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On-going tasks

• Multipath study
• Localization experiments
• In free space, rural and urban environments
• Comparison with MATLAB simulations
• Coherent receivers
• Comparison in complexity with non-coherent
  receivers
• Comparison in cost with non-coherent receivers
• Miniaturization aspect
• Integration of the solution
• Final power-consumption

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Conclusion

• THALES UWB IR main features
• fc3.35, 3.85, GHz, BW500MHz
• 4ns Gaussian Pulse with PRF of 25MHz/2.5MHz
• OOK modulation
• ? Very low complexity, Very low cost (radio with
  a few components)
• ? Scalable (25Mbps at 10m, , 350kbps at 70m, )
• Location Awareness
• Two possible modes TWR or OWR
• 75cm in 70m region (AWGN)