January 2005

Namhyong et al., ProposalSlide 1

doc.: IEEE 802.15-05-0042-00-004a

Submission

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: Samsung DM R&D Center ProposalDate Submitted: XX December, 2004Source: Namhyong Kim et al., Samsung Electronics Digital Media R&D CenterAddress 416 Maetan 3 Dong, Yeongtong Gu, Suwon City, Gyongi Do, Korea, 443-742 Voice: 82 31 200 8783, FAX: 82 31 200 3350 , E-Mail: namhyong.kim@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.

January 2005

Namhyong et al., ProposalSlide 2

doc.: IEEE 802.15-05-0042-00-004a

Submission

Samsung DM R&D Center Proposal

Multiple Access and Range Methodology

for Chaos DCSK System

Namhyong Kim, Inhwan Kim

Samsung Electronics Co., Ltd.

DM R&D Center

January 2005

Namhyong et al., ProposalSlide 3

doc.: IEEE 802.15-05-0042-00-004a

Submission

Contents

• Overview• Chaotic System Simulator

– Chaotic Sources

– DCSK ( Differential Chaotic Shift Keying )

• Issues result from Chaos Signal• Range Estimation based on Chaos Signal• Conclusion

January 2005

Namhyong et al., ProposalSlide 4

doc.: IEEE 802.15-05-0042-00-004a

Submission

Overview

• Chaotic Communication Simulator– System Parameters

– Chaotic Source

– Modulation

• Issues– Simultaneously Operating Piconets

• Range Estimation– High precision Distance Measurement by TOA

January 2005

Namhyong et al., ProposalSlide 5

doc.: IEEE 802.15-05-0042-00-004a

Submission

Contents

• Overview• Chaotic System Simulator

– Chaotic Sources

– DCSK ( Differential Chaotic Shift Keying )

• Issues result from Chaos Signal• Range Estimation based on Chaos Signal• Conclusion

January 2005

Namhyong et al., ProposalSlide 6

doc.: IEEE 802.15-05-0042-00-004a

Submission

Simulation Parameters

• Frequency Band– Bandwidth : 2 GHz

– Center Frequency : 4 GHz

• Bit Frame– 1 bit time frame : 200 ns (5 MHz)

– Duty Cycle : 50 % (100 ns)

• Sampling– Simulation Sampling Frequency: 40 GHz

January 2005

Namhyong et al., ProposalSlide 7

doc.: IEEE 802.15-05-0042-00-004a

Submission

Chaotic Sources

• Pseudo-random Sequence• Ordinary Differential Equation

January 2005

Namhyong et al., ProposalSlide 8

doc.: IEEE 802.15-05-0042-00-004a

Submission

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 < f < 0.25– Stopband : f < 0.14 or 0.28 < f– Ws Attenuation : 15 dB– Wp Ripple : 1 dB

January 2005

Namhyong et al., ProposalSlide 9

doc.: IEEE 802.15-05-0042-00-004a

Submission

Chaotic Signal Characterictic(1)

• Regulated Spectrumby Filtering

• However, at most,Quasi-Chaos Source

January 2005

Namhyong et al., ProposalSlide 10

doc.: IEEE 802.15-05-0042-00-004a

Submission

2nd Order Differential Equation with 4.5 Freedom

Tx1′ + x1 = mF(x5)

x2′′ + α2 x2′ + ω22x2 = ω2

2x1 x3′′ + α3 x3′ + ω3

2x3 = α3 x2′ x4′′ + α4 x4′ + ω4

2x4 = α4 x3′x5′′ + α5 x5′ + ω5

2x5 = α5 x4′

where,

F(x) = ｜ x+e1 ｜ - ｜ x-e1 ｜ +0.5( ｜ x-e2 ｜ - ｜ x+e2 ｜ )

m=110, 2=0.3, 3=0.7, 4=0.7,

5=0.6, 2=1, 3=0.86, 4=0.73,

5=0.6, T=1.25, e1=0.5, e2=1

Runge-Kutta Method

x1′= (mF(x5) - X1)/T

x2′= ω22(X1- X3)

x3′= X2 - α2X3

x4′= α2x3′- ω22X5

x5′= X4 - α2X5

x2′′= α2x5′- ω32X7

x3′′= X6 - α2X7

x4′′= α4x3′′-ω32X9

x5′′= X8 - α4X9

January 2005

Namhyong et al., ProposalSlide 11

doc.: IEEE 802.15-05-0042-00-004a

Submission

Chaotic Signal Characterictic(2)

• Chaotic Signal directlygenerated from ODE45

• Direct UWB signal madefrom simple TR & RLCcircuitry analyzable by2nd order differential equation

January 2005

Namhyong et al., ProposalSlide 12

doc.: IEEE 802.15-05-0042-00-004a

Submission

Modulation

• Differential Chaotic Shift Keying

January 2005

Namhyong et al., ProposalSlide 13

doc.: IEEE 802.15-05-0042-00-004a

Submission

DCSK System Schematics

Delay

T/2

Threshold decision Integrator

/ 2( )

Tdt

Direct Chaos Generator

Delay

T/2-1

RX

TX

Diplexer

January 2005

Namhyong et al., ProposalSlide 14

doc.: IEEE 802.15-05-0042-00-004a

Submission

Differential Operation

Template Bit Info Bit

Original Frame

Half bit duration Delayed Frame

Multiplication

Half bit duration

Integration

1

0

January 2005

Namhyong et al., ProposalSlide 15

doc.: IEEE 802.15-05-0042-00-004a

Submission

Time Slot Jittered

No Jitter

200 ps Jitter

300 ps Jitter

January 2005

Namhyong et al., ProposalSlide 16

doc.: IEEE 802.15-05-0042-00-004a

Submission

DCSK Performance (32 Octet)

BER PER (200 Frames)

January 2005

Namhyong et al., ProposalSlide 17

doc.: IEEE 802.15-05-0042-00-004a

Submission

Contents

• Overview• Chaotic System Simulator

– Chaotic Sources

– DCSK ( Differential Chaotic Shift Keying )

• Issues result from Chaos Signal• Range Estimation based on Chaos Signal• Conclusion

January 2005

Namhyong et al., ProposalSlide 18

doc.: IEEE 802.15-05-0042-00-004a

Submission

Strong Features

• Flat spectrum generated by unpredictable genuine random sequence

• Nearly infinite resourceful orthogonal code sets • Immunity against multi-path fading• Low complexity and cost circuitry from direct

generation of UWB signal• Good signal spectrum nature from

Bandwidth/Bit rate > 1

January 2005

Namhyong et al., ProposalSlide 19

doc.: IEEE 802.15-05-0042-00-004a

Submission

Weak Features

• 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 (> 2 GHz)– Difficult to apply accurate estimation method

– Location Awareness/Range Problem

January 2005

Namhyong et al., ProposalSlide 20

doc.: IEEE 802.15-05-0042-00-004a

Submission

SOP options for Chaos System

• Code Division– High Sampling Clock– High Cost and Overhead

• Frequency Division– Range Resolution Degradation– Almost only solution for 3 ~ 4 piconets in 3 ~ 5 GHz band

• Time Division– No fit in SOP Physical Selection Criterion

due to Uncoordinated Piconets– Possible solution under Assumption of Global

time synchronization & low duty cycle

January 2005

Namhyong et al., ProposalSlide 21

doc.: IEEE 802.15-05-0042-00-004a

Submission

Time Division SOP

January 2005

Namhyong et al., ProposalSlide 22

doc.: IEEE 802.15-05-0042-00-004a

Submission

System Block

Data Bit FrameGenerator

Chaos SignalGenerator

Data 01101101

Data -111-111-11

Template

Chaos Receiver

Data 01101101

January 2005

Namhyong et al., ProposalSlide 23

doc.: IEEE 802.15-05-0042-00-004a

Submission

Piconet1

Piconet2

Template Bit

Bit Frame

Transmission

T1 D1nD11 T2 D2nD21T1 D1nD11 T2 D2nD21

D11 D2nD21D1nT1 T2

Frame1

Frame2

January 2005

Namhyong et al., ProposalSlide 24

doc.: IEEE 802.15-05-0042-00-004a

Submission

Receiver Details

Template

Data

1 1 0 ………. 0 1 bit Duration

∫

Integrator

Z

Z

Z

Z

January 2005

Namhyong et al., ProposalSlide 25

doc.: IEEE 802.15-05-0042-00-004a

Submission

Signal Processing

User11100111110

User21101110110

User30100111010

Multi_path Channel

January 2005

Namhyong et al., ProposalSlide 26

doc.: IEEE 802.15-05-0042-00-004a

Submission

Contents

• Overview• Chaotic System Simulator

– Chaotic Sources

– DCSK ( Differential Chaotic Shift Keying )

• Issues result from Chaos Signal• Range Estimation based on Chaos Signal• Conclusion

January 2005

Namhyong et al., ProposalSlide 27

doc.: IEEE 802.15-05-0042-00-004a

Submission

Range Block Diagram

Envelop Detection&

Signal Point DetectionZ-1 Serial-to-Parallel

Delay Circuit

January 2005

Namhyong et al., ProposalSlide 28

doc.: IEEE 802.15-05-0042-00-004a

Submission

Coordinator Device

Source Time Counter+ Target Time Counter

Source Time Counter

Source Time Counter+ Target Time Counter1. Offset by

Comparison between (Source Time Counter - Target Time Counter) & (Source Time Counter - Source2 Time Counter)

2. Distance from (Source Time Counter - Source2 Time Counter)

- Offset

+ Offset

0

Adjusting Time CounterBy Offset

Confirm CounterJustification

Completion

January 2005

Namhyong et al., ProposalSlide 29

doc.: IEEE 802.15-05-0042-00-004a

Submission

Time Counter Adjust Example

Initial : 356 358

Device (-2 Offset) Coordinator

1st Pass : 364 356+8 374 358+161. PNC recalculates Device Arrival time : 366 358 + (16/2)2. Compare value from 1 and Device : -2 364 – 3663. +2 Transferred as –Offset4. 8 Kept for Distance between PNC and Device

January 2005

Namhyong et al., ProposalSlide 30

doc.: IEEE 802.15-05-0042-00-004a

Submission

Location Awareness Special Mode

1. Timing Counter Fine Synchronization1. PNC disseminates special frame to inform Device

of Location special mode2. Device acknowledges with its own timing count3. PNC compares its own count with Device’s count,

and extract an offset between them4. PNC sends negative offset in order for Device to

compensate its timer5. Device informs PNC of all being set

January 2005

Namhyong et al., ProposalSlide 31

doc.: IEEE 802.15-05-0042-00-004a

Submission

∇ X

∇ Y

Template Frame Data Frame

Data

Template

Envelop Detection

Delay Circuit by 1~3 ns

January 2005

Namhyong et al., ProposalSlide 32

doc.: IEEE 802.15-05-0042-00-004a

Submission

Fine Precision TOA Estimation

• Suggest Special mode different from Normal mode, which needs faster clock

• In special mode, Estimate how far Signal detached from fixed time slot with finer clock

• This obtained value returned with Response

command to Request command from MAC

January 2005

Namhyong et al., ProposalSlide 33

doc.: IEEE 802.15-05-0042-00-004a

Submission

Delay Circuit

Phase 0

Phase 90

Phase 180

Phase 270

100 MHz

2.5 ns

January 2005

Namhyong et al., ProposalSlide 34

doc.: IEEE 802.15-05-0042-00-004a

Submission

Simulation (BNR 16dB)

real distance : 0.968 meter2.5 ns precision distance : 0.750 meterError : -0.218 meter

real distance : 13.118 meter2.5 ns precision distance : 12.750 meterError : -0.367 meter

Maximum Index of Moving Average by duty cycleDuration will be convertedto distance.

January 2005

Namhyong et al., ProposalSlide 35

doc.: IEEE 802.15-05-0042-00-004a

Submission

Conclusion

• Chaotic Communication System Simulator– Source Generation

– DCSK modulation

• Chaos System Issues– Chaos Signal Features

– SOP solutions

• Ranging– Fine distance estimation by using Chaos Signal

January 2005

Namhyong et al., ProposalSlide 36

doc.: IEEE 802.15-05-0042-00-004a

Submission

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.