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

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title:Samsung DM R&D Center Proposal Date Submitted: XX December, 2004 Source:Namhyong Kim et al., Samsung Electronics Digital Media R&D Center Address 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. Namhyong et al., Proposal

2. 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 Namhyong et al., Proposal

3. Contents • Overview • Chaotic System Simulator • Chaotic Sources • DCSK( Differential Chaotic Shift Keying ) • Issues result from Chaos Signal • Range Estimation based on Chaos Signal • Conclusion Namhyong et al., Proposal

4. Overview • Chaotic Communication Simulator • System Parameters • Chaotic Source • Modulation • Issues • Simultaneously Operating Piconets • Range Estimation • High precision Distance Measurement by TOA Namhyong et al., Proposal

5. Contents • Overview • Chaotic System Simulator • Chaotic Sources • DCSK( Differential Chaotic Shift Keying ) • Issues result from Chaos Signal • Range Estimation based on Chaos Signal • Conclusion Namhyong et al., Proposal

6. 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 Namhyong et al., Proposal

7. Chaotic Sources • Pseudo-random Sequence • Ordinary Differential Equation Namhyong et al., Proposal

8. 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 Namhyong et al., Proposal

9. Chaotic Signal Characterictic(1) • Regulated Spectrumby Filtering • However, at most,Quasi-Chaos Source Namhyong et al., Proposal

10. 2nd Order Differential Equation with 4.5 Freedom 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 Tx1′ + x1 = mF(x5) x2′′ + α2x2′ + ω22x2= ω22x1 x3′′ + α3x3′ + ω32x3 = α3x2′ x4′′ + α4x4′ + ω42x4 = α4x3′ x5′′ + α5x5′ + ω52x5 = α5x4′ 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 Namhyong et al., Proposal

11. Chaotic Signal Characterictic(2) • Chaotic Signal directlygenerated from ODE45 • Direct UWB signal madefrom simple TR & RLCcircuitry analyzable by2nd order differential equation Namhyong et al., Proposal

12. Modulation • Differential Chaotic Shift Keying Namhyong et al., Proposal

13. TX • Direct Chaos Generator Delay T/2 Diplexer -1 Delay T/2 Integrator • Threshold decision RX DCSK System Schematics Namhyong et al., Proposal

14. Info Bit Differential Operation Template Bit Original Frame Multiplication Half bit duration Delayed Frame Half bit duration Integration 1 0 Namhyong et al., Proposal

15. Time Slot Jittered 300 ps Jitter No Jitter 200 ps Jitter Namhyong et al., Proposal

16. DCSKPerformance (32 Octet) BER PER (200 Frames) Namhyong et al., Proposal

17. Contents • Overview • Chaotic System Simulator • Chaotic Sources • DCSK( Differential Chaotic Shift Keying ) • Issues result from Chaos Signal • Range Estimation based on Chaos Signal • Conclusion Namhyong et al., Proposal

18. 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 Namhyong et al., Proposal

19. WeakFeatures • 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 Namhyong et al., Proposal

20. 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 Namhyong et al., Proposal

21. Time Division SOP Namhyong et al., Proposal

22. Data -111-111-11 Data 01101101 Data Bit Frame Generator Chaos Signal Generator Template Data 01101101 Chaos Receiver System Block Namhyong et al., Proposal

23. Template Bit T1 T1 D11 D11 D1n D1n T2 T2 D21 D21 D2n D2n Piconet1 T1 D11 D1n T2 D21 D2n Piconet2 Bit Frame Transmission Frame1 Frame2 Namhyong et al., Proposal

24. Integrator Data ∫ Z Template 1 bit Duration Z Z 1 1 0 ………. 0 Z Receiver Details Namhyong et al., Proposal

25. Signal Processing User1 1100111110 Multi_path Channel User2 1101110110 User3 0100111010 Namhyong et al., Proposal

26. Contents • Overview • Chaotic System Simulator • Chaotic Sources • DCSK( Differential Chaotic Shift Keying ) • Issues result from Chaos Signal • Range Estimation based on Chaos Signal • Conclusion Namhyong et al., Proposal

27. Envelop Detection & Signal Point Detection Serial-to-Parallel Z-1 Delay Circuit Range Block Diagram Namhyong et al., Proposal

28. Device Coordinator Source Time Counter Source Time Counter + Target Time Counter Source Time Counter + Target Time Counter • Offset by Comparison between (Source Time Counter - Target Time Counter) & (Source Time Counter - Source2 Time Counter) • Distance from (Source Time Counter - Source2 Time Counter) - Offset Adjusting Time Counter By Offset + Offset Confirm Counter Justification 0 Completion Namhyong et al., Proposal

29. Time Counter Adjust Example Device (-2 Offset) Coordinator Initial : 356 358 1st Pass : 364  356+8 374  358+16 1. PNC recalculates Device Arrival time : 366  358 + (16/2) 2. Compare value from 1 and Device : -2  364 – 366 3. +2 Transferred as –Offset 4. 8 Kept for Distance between PNC and Device Namhyong et al., Proposal

30. 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 Device’s 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 Namhyong et al., Proposal

31. Data Template Template Frame Data Frame ∇ X ∇ Y Envelop Detection Delay Circuit by 1~3 ns Namhyong et al., Proposal

32. 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 Responsecommand to Request command from MAC Namhyong et al., Proposal

33. 100 MHz Phase 0 Phase 90 Phase 180 Phase 270 2.5 ns Delay Circuit Namhyong et al., Proposal

34. Simulation (BNR 16dB) Maximum Index ofMoving 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 Namhyong et al., Proposal

35. 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 Namhyong et al., Proposal

36. 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. Namhyong et al., Proposal