Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

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Project IEEE P802.15 Working Group for Wireless
Personal Area Networks (WPANs) Submission Title
Samsung DM RD Center Proposal Date Submitted
XX December, 2004 Source Namhyong Kim et al.,
Samsung Electronics Digital Media RD
Center Address 416 Maetan 3 Dong, Yeongtong Gu,
Suwon City, Gyongi Do, Korea, 443-742 Voice 82
31 200 8783, FAX [phone] , E-Mail
namhyong.kim_at_samsung.com Re Response to Call
for Proposals Abstract Purpose Proposing a
PHY-layer interface for standardization by
802.15.4a 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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• Samsung DM RD Center Proposal
• Multiple Access and Range Methodology
• for Chaos DCSK System
• Namhyong Kim, Inhwan Kim
• Samsung Electronics DM RD Center

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Contents

• Nature of Chaos Signal
• DCSK ( Differential Chaotic Shift Keying )
• SOP over Chaos Communication System
• Range over Chaos Communication System
• Conclusion

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• Chaotic Source
• Pseudo-random Sequence
• Ordinary Differential Equation

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Pseudo-Random Sequence

• Pseudo-Chaos Signal Generator
• Pseudo-random Sequence filtered by Chebyshev
  Type I
• Pseudo-random numbersranging between -1.0 to
  1.0
• Chebyshev Specification
• Passband 0.15 lt f lt 0.25
• Stopband f lt 0.14 or 0.28 lt f
• Ws Attenuation 15 dB
• Wp Ripple 1 dB

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Chaotic Signal Characterictic(1)

• Regulated Spectrumby Filtering
• However, at most,Quasi-Chaos Source

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2nd Order Differential Equation with 4.5 Freedom
Runge-Kutta Method x1' (mF(x5) - X1)/T
x2' ?22(X1- X3) x3' X2 - a2X3 x4' a2x3'-
?22X5 x5' X4 - a2X5 x2'' a2x5'- ?32X7 x3'' X6
- a2X7 x4'' a4x3''-?32X9 x5'' X8 - a4X9

• Tx1' x1 mF(x5)
• x2'' a2 x2' ?22x2 ?22x1
• x3'' a3 x3' ?32x3 a3 x2'
• x4'' a4 x4' ?42x4 a4 x3'
• x5'' a5 x5' ?52x5 a5 x4'
• where,
• F(x) xe1- x-e10.5(x-e2- xe2)
• m110, ?20.3, ?30.7, ?40.7,
• ?50.6, ?21, ?30.86, ?40.73,
• ?50.6, T1.25, e10.5, e21

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Chaotic Signal Characterictic(2)

• Chaotic Signal directlygenerated from ODE45
• Direct UWB signal madefrom simple TR
  RLCcircuitry analyzable by2nd order
  differential equation

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Strong Features

• Pros
• Flat spectrum generated by unpredictable random
  sequence
• Nearly infinite resourceful orthogonal code sets
  
• Immunity against multipath fading
• Low complexity and cost circuitry from direct
  generation of UWB signal
• Good signal spectrum nature from Bandwidth/Bit
  rate gt 1

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Weak Features

• Cons
• Nearly impossibility of the Same Signal
  Regeneration
• Impossible to brew the same signal template in
  the receiver side
• Hard to resolve Multiple Access/Simultaneous
  Operating Piconet and High resolution Range
  Problem
• High Sampling Problem from UWB (gt 2 GHz)
• Difficult to apply accurate estimation method
• Location Awareness/Range Problem

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Contents

• Nature of Chaos Signal
• DCSK ( Differential Chaotic Shift Keying )
• SOP over Chaos Communication System
• Range over Chaos Communication System
• Conclusion

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DCSK System Schematics
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DCSK Performance
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Contents

• Nature of Chaos Signal
• DCSK ( Differential Chaotic Shift Keying )
• SOP over Chaos Communication System
• Range over Chaos Communication System
• Conclusion

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Issue on SOP of Chaos system

• Code Division
• High Sampling Clock
• Frequency Division
• Range Resolution Degradation
• Time Division
• No fit in Physical Selection Criterion on
  Uncoordinated Piconets

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Chaos System Block
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Transmission
Frame1
Frame2
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Receiver Details
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Signal Processing
User1 1100111110
Multi_path Channel
User2 1101110110
User3 0100111010
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Contents

• Nature of Chaos Signal
• DCSK ( Differential Chaotic Shift Keying )
• SOP over Chaos Communication System
• Range over Chaos Communication System
• Conclusion

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LOA Block Diagram
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(No Transcript)
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Time Counter Adjust
Device
PNC
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Location Awareness Special Mode

• Timing Counter Fine Synchronization
• PNC disseminates special frame to inform
  Deviceof Location special mode
• Device acknowledges with its own timing count
• PNC compares its own count with Devices
  count,and extract an offset between them
• PNC sends negative offset in order for Device
  tocompensate its timer
• Device informs PNC of all being set

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Template Frame
Data Frame
? X
? Y
Envelop Detection
Delay Circuit by 13 ns
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Delay Circuit
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Simulation (BNR 16dB)
Maximum Index of Moving Average by duty
cycle Duration will be converted to distance.
real distance 0.968 meter 2.5 ns precision
distance 0.750 meter Error -0.218 meter
real distance 13.118 meter 2.5 ns precision
distance 12.750 meter Error -0.367 meter
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Conclusion

• DCSK (Differential Chaotic Shift Keying)
  Modulation
• Issues at SOP (Simultaneously Operating Piconet)
  at Chaos system
• Location Awareness at Chaos system

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References

• Kolumbán, G., Kennedy, M.P., Jákó, Z. and Kis,
  G., "Chaotic Communications with Correlator
  Receivers Theory and Performance Limits,"
  Special Issue of The IEEE Proceedings on chaotic
  communications, 2002.
• Kolumbán, G. and Kennedy, M.P., "Correlator-Based
  Chaotic Communications Attainable Noise and
  Multipath Performance," in "Chaos in Circuits and
  Systems," (G. Chen editor), Birkhauser, Boston,
  2002.
• Dmitriev A.S., Efremova E.V, and Maksimov N.A.
  Controlling the spectrum envelope in
  single-transistor generator of chaotic
  oscillations, Radiotekhnika i elektronika, 2004,
  vol. 49, no. 2, pp. 222-227 (in Russian).
• Dmitriev A.S., Kyarginsky B.Ye., Panas A.I., and
  Starkov S.O., "Experiments on ultra wideband
  direct chaotic information transmission in
  microwave band", Int. J. Bifurcation Chaos,
  2003, vol. 13, No. 6, pp. 1495-1507.