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: [PSWF-based SSA Pulse Wavelets and Ternary Complementary Sets for DS-UWB ] Date Submitted: [13 September, 2004] Source: [(1) Honggang Zhang, (1) Imrich Chlamtac, (2) Chihong Cho, and (2) Masao Nakagawa ] Company [ (1) Create-Net, (2) Keio University ] Connector’s Address [Via Solteri, 38, 38100 Trento, ITALY] Voice:[+39-0461-828584 ], FAX: [+39-0461-421157 ], E-Mail: ［honggang.zhang@create-net.it, imrich.chlamtac@create-net.it, cho@nkgw.ics.keio.ac.jp, nakagawa@nkgw.ics.keio.ac.jp] Re: [IEEE P802.15 Alternative PHY Call For Proposals, IEEE P802.15-02/327r7] Abstract: [In order to realize scalable data rate transmission for IEEE 802.15.3a UWB WPAN, PSWF-based SSA pulse wavelets and ternary complementary sets are investigated for DS-UWB. ] Purpose: [For investigating the characteristics of High Rate Alternative PHY standard in 802.15TG3a based on the PSWF-type SSA pulse wavelets and ternary complementary sets. ] 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. Honggang ZHANG, Create-Net

2. PSWF-based SSA Pulse Wavelets and Ternary Complementary Sets for DS-UWB Honggang ZHANG, Imrich CHLAMTAC Create-Net, Italy Chihong CHO, Masao NAKAGAWA Keio University, Japan Honggang ZHANG, Create-Net

3. Outline of presentation Overview of previous improvements in DS-UWB PSWF-type SSA pulse wavelets for DS-UWB Ternary complementary sets for DS-UWB Improving DS-UWB by combining PSWF-type SSA pulse wavelets with ternary complementary sets 5. Conclusion remarks 6. Backup materials Honggang ZHANG, Create-Net

4. CREATE-NET Honggang ZHANG, Create-Net

5. Create-Net in Trento, Italy Honggang ZHANG, Create-Net

6. 1. Overview of previous improvements in DS-UWB • Support for much higher data rates • BPSK modulation using variable length spreading codes • At same time, much lower complexity and power • Essential for mobile & handheld applications • Digital complexity is 1/3 of previous estimates, yet provides good performance at long range and high rates at short range • Harmonization & interoperability with MB-OFDM through the Common Signaling Mode (CSM) • A single multi-mode PHY with both DS-UWB and MB-OFDM • Best advantages of both approaches with most flexibility Honggang ZHANG, Create-Net

7. DS-UWB operating bands & SOP Low Band High Band 3 4 5 6 7 8 9 10 11 3 4 5 6 7 8 9 10 11 GHz GHz • Each piconet operates in one of two bands • Low band (below U-NII, 3.1 to 4.9 GHz) • High band (optional, above U-NII, 6.2 to 9.7 GHz) • Support for multiple piconets • Classic spread spectrum approach • Acquisition uses unique length-24 spreading codes • Chipping rate offsets to minimize cross-correlation Honggang ZHANG, Create-Net

8. N division 2. PSWF-type SSA pulse wavelets for DS-UWB Honggang ZHANG, Create-Net

9. Designing PSWF-based SSA pulse wavelets Prolate Spheroidal Wave Functions (PSWF) • Not just trying to construct a pulse waveform in order to satisfy the FCC spectral mask, on the contrary, first starting from considering a required spectral mask in frequency domain (band-limited), and then finding its corresponding pulse waveform in time domain (time-limited). • Just as C. E. Shannon has asked a question once upon a time, “To what extent are the functions which confined to a finite bandwidth also concentrated in the time domain? ”, which has given rise to the discovery and usage of Prolate Spheroidal Wave Functions (PSWF) in the sixties. • Designing a time-limited & band-limited pulse waveform is extremely important in UWB system. Honggang ZHANG, Create-Net

10. Features of PSWF-based pulse wavelets • Pulse waveforms are doubly orthogonal to each other. • Pulse-width and bandwidth can be simultaneously controlled to match with arbitrary spectral mask adaptively. • Pulse-width can be kept same for all orders of m. • Pulse bandwidth is same for all orders of m. • They can be utilized for simple transceiver implementation since frequency shift, e.g., up-conversion or down-conversion with mixer as in former MB-OFDM and DS-UWB of IEEE 802.15.3a is no longer necessary. Honggang ZHANG, Create-Net

11. 5 GHz W-LAN Power (dB) 1 2 3 4 5 6 7 8 9 10 11 f Orthogonal PSWF-based SSA pulse wavelets (3.1-5.6 GHz, order of 1, 2, 3 and 4) Honggang ZHANG, Create-Net

12. 3.960GHz 572MHz 572MHz 572MHz 572MHz 572MHz 572MHz 3.692GHz 3.120GHz 4.264GHz 4.836GHz 4.836GHz 3.120GHz 0 -3 1 2 3 -20 4.264GHz 3.120GHz 3.692GHz 4.836GHz 3432 3960 4488 Frequency (MHz) 3100 5100 ImprovingCommon Signaling Mode (CSM) based on PSWF-type SSA pulse wavelets 1 3 1+2 2+3 Honggang ZHANG, Create-Net

13. Orthogonal PSWF pulse wavelet generation (3.120-4.264 GHz, order of 1, 2, 3 and 4) Honggang ZHANG, Create-Net

14. Orthogonal PSWF pulse wavelet generation (3.692-4.836 GHz, order of 1, 2, 3 and 4) Honggang ZHANG, Create-Net

15. Dual-band PSWF pulse wavelet generation (3.120-3.692 GHz, 4.264-4.836 GHz) Honggang ZHANG, Create-Net

16. Symbol duration Chip duration 3. Ternary complementary sets for DS-UWB PSWF-type SSA pulses Ternary complementary set Reference: Di Wu, P. Spasojevic, and Ivan Seskar, “Ternary complementary sets for orthogonal pulse based UWB,” 37th Asilomar Conference on Signals, Systems and Computers, Nov. 9-12, 2003. Honggang ZHANG, Create-Net

17. Design ternary complementary sets Honggang ZHANG, Create-Net

18. Design ternary MO (mutually orthogonal) complementary sets Honggang ZHANG, Create-Net

19. Design ternary MO complementary sets (cont.) Honggang ZHANG, Create-Net

20. Design ternary MO complementary sets (cont.) Honggang ZHANG, Create-Net

21. 1.E+00 1.E-01 BER 1.E-02 Ternary MO complementary set N=8 Ternary complementary set N=7 1.E-03 M-sequence N=31 M-sequence N=15 1.E-04 2 4 6 8 10 12 Eb/No (dB) BER vs. Eb/No (CM1, multi-users: 4) Honggang ZHANG, Create-Net

22. 1.E+00 1.E-01 BER 1.E-02 Walsh Code N=8 Goldlike Sequence N=15 M-sequence N=31 1.E-03 Goldlike Sequence N=63 Ternary MO Complementary Sets N=8 1.E-04 2 4 6 8 10 12 Eb/No (dB) BER vs. Eb/No (CM1, multi-users: 8) Honggang ZHANG, Create-Net

23. 4. Improve DS-UWB utilizing PSWF-type SSA pulse wavelets and ternary complementary sets DS-UWB scaling to higher rates • There is significant interest in “cable replacement” applications that require high speed operation (480+ Mbps) at short range • Current DS-UWB operation at 500 Mbps uses L=2 code & ¾ FEC • Complexity is similar DS-UWB receiver for 110 & 220 Mbps • Same ADC bit widths & clock rates • Same rake bit width & complexity • Fewer Rake taps available (only 2/3 as many as for 220 Mbps) • Viterbi decoder for k=6, rate ¾ likely 2x gates  45k gate increase • Current operation at 660 Mbps also supported with un-coded operation • 4.9 m range in fully impaired AWGN simulation • Eliminates requirement for high speed Viterbi decoder Honggang ZHANG, Create-Net

24. DS-UWB signal generation Input Data Scrambler K=6 FEC Encoder Conv. Bit Interleaver Bit-to-Code Mapping Pulse Shaping Center Frequency Gray or Natural mapping K=4 FEC Encoder 4-BOK Mapper Transmitter blocks required to support optional modes • Data scrambler using 15-bit LFSR (same as 802.15.3) • Constraint-length k=6 convolutional code • K=4 encoder can be used for lower complexity at high rates or to support iterative decoding for enhanced performance. • Convolutional bit interleaver protects against burst errors • Variable length codes provide scalable data rates using BPSK • Support for optional 4-BOK modes with little added complexity Honggang ZHANG, Create-Net

25. Data rates supported by DS-UWB (low-band) Similar modes have defined for high band Honggang ZHANG, Create-Net

26. High data rate applications • Critical for cable replacement applications such as wireless USB (480 Mbps) and Wireless 1394 (400 Mbps) • High rate device supporting 480+ Mbps • DS-UWB device uses shorter codes (L=2, symbol rate 660 MHz) • Uses same ADC rate & bit width (3 bits) and rake tap bit widths • Rake combining: use fewer taps at a higher rate or same taps with extra gates • Viterbi decoder complexity is ~2x the baseline k=6 decoder • Can operate at 660 Mbps without Viterbi decoder for super low power Honggang ZHANG, Create-Net

27. 5. Conclusion remarks • PSWF-type pulse wavelets have been proposed for improving DS-UWB performance. • We also have analyzed the ternary MO complementary code sets for DS-UWB with higher data rate. • Scalable and adaptive performance improvement can be expected by utilizing the PSWF-based SSA-UWB and ternary MO complementary sets. Honggang ZHANG, Create-Net

28. 6. Background materials Honggang ZHANG, Create-Net

29. N division Design PSWF-based SSA pulse wavelets Honggang ZHANG, Create-Net

30. Realization of SSA-UWB pulse wavelet design Prolate Spheroidal Wave Functions (PSWF) • Not just trying to construct a pulse waveform in order to satisfy the FCC spectral mask, on the contrary, first starting from considering a required spectral mask in frequency domain (band-limited), and then finding its corresponding pulse waveform in time domain (time-limited). • Just as C. E. Shannon has asked a question once upon a time, “To what extent are the functions which confined to a finite bandwidth also concentrated in the time domain?”, which has given rise to the discovery and usage of Prolate Spheroidal Wave Functions (PSWF) in the sixties. • Designing a time-limited & band-limited pulse waveform is extremely important in UWB system. Honggang ZHANG, Create-Net

31. 5 GHz W-LAN Power 　Spectrum 1 4 5 6 8 9 10 11 2 3 7 f [GHz] Designing method of optimized SSA-UWB wavelets using PSWF Honggang ZHANG, Create-Net

32. Designing method of optimized SSA-UWB wavelets using PSWF (cont.) Honggang ZHANG, Create-Net

33. What’s Prolate Spheroidal Wave Functions (PSWF)? Honggang ZHANG, Create-Net

34. Characteristics of PSWF-based pulse wavelets • Pulse waveforms are doubly orthogonal to each other. • Pulse-width and bandwidth can be simultaneously controlled to match with arbitrary spectral mask adaptively. • Pulse-width can be kept same for all orders of m. • Pulse bandwidth is same for all orders of m. • They can be utilized for simple transceiver implementation since frequency shift, e.g., up-conversion or down-conversion with mixer as in MB-OFDM and DS-UWB of IEEE 802.15.3a is no longer necessary. Honggang ZHANG, Create-Net

35. Numerical solution of PSWF Honggang ZHANG, Create-Net

36. Numerical solution of PSWF (cont.) Discrete-time solution of Prolate Spheroidal Wave Functions (PSWF) with eigenvalue decomposition Honggang ZHANG, Create-Net

37. 5 GHz W-LAN Power 　Spectrum 1 4 5 6 8 9 10 11 2 3 7 f [GHz] Optimized pulse waveform generation based on PSWF 0.4 0.3 0.2 0.1 Relative Amplitude 0 -0.1 -0.2 ____ order of 1 _ _ _ order of 2 ........ order of 3 -0.3 -0.4 -5 -4 -3 -2 -1 0 1 2 3 4 5 -10 Time (sec) x 10 Orthogonal pulse waveform generation based on PSWF (3.1-10.6 GHz, order of 1, 2 and 3). Honggang ZHANG, Create-Net

38. Optimized pulse waveform generation based on PSWF Optimized pulse waveform generation based on PSWF 0.3 0.4 0.2 0.3 0.2 0.1 0.1 0 Relative Amplitude Relative Amplitude 0 -0.1 -0.1 -0.2 -0.2 -0.3 ___ order of 1 …... order of 2 ___ order of 3 …... order of 4 -0.3 -0.4 -1.5 -1 -0.5 0 0.5 1 1.5 -0.4 -1.5 -1 -0.5 0 0.5 1 1.5 -9 Time (second) x 10 -9 Time (second) x 10 Orthogonal pulse waveform generation based on PSWF (3.1-5.6 GHz, order of 1, 2, 3 and 4). Honggang ZHANG, Create-Net