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: [Multicarrier-UWB] Date Submitted: [8 March 2003] Source: [Ahmed H Tewfik] Company [University of Minnesota] Address [Dept. of Electrical and Computer Engineering, Room 4-174 EECS Bldg.,Minneapolis, MN 55455] Voice:[612-625-6024], FAX: [612-625-4583], E-Mail:[tewfik@ece.umn.edu] Re: [03147r0P802-15_TG3a-University-of-Minnesota-CFP-Presentation.ppt] Response to a Call for Contributions Task Group 3a Call For Intent and Proposals, November 2002, updated January 2003, 02371r0P802-15_SG3a-5_Criteria.doc Abstract: [We propose a multi-carrier UWB system for WPAN communications. We describe system design issues and proposed transmitter and receiver structures. We also provide a self-evaluation of the proposed system.] Purpose: [For consideration by 802.15.3a task group.] 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. Tewfik/Saberinia, U. of MN

2. Fast Frequency HoppingUWB-OFDM H. Tewfik and E. Saberinia University of Minnesota Tewfik/Saberinia, U. of MN

3. Overview • FFH-UWB-OFDM: compromise between multi-UWB and pure OFDM • Proposed System • System comparisons and design trade-offs • Transmitter and Receiver Structure • Link Budget • Performance of the System • Coexistence and Multiple piconets • Complexity and Power Consumption • D/A and A/D structure • Conclusion Tewfik/Saberinia, U. of MN

4. Multi-Carrier UWB • Multi-band UWB • Need multiple band transmitter • Need a block of analog matched filters • Pure OFDM UWB • No need for Rake receiver • Need heavy coding to extract frequency diversity • Long FFT and IFFT • FFH-UWB-OFDM (some where between!) • No need for Rake receiver • Implemented short IFFT and FFT technology • Extract multipath diversity and use smaller number of Subcarriers Tewfik/Saberinia, U. of MN

5. An FFH-UWB-OFDM Block • Make an OFDM block with N-IFFT of QAM symbols (N=32) • Create a base band signal with bandwidth W> 500 MHz and Duration Tu ns f(MHz) W 0 31 30 1 0 0 Tu t Tewfik/Saberinia, U. of MN

6. An FFH-UWB-OFDM Block • Fast frequency hopping inside the block to achieve multipath resolution and frequency spreading • Avoid UNII band • Use only 3.1-4.8 GHz (Lower Band System) • Use whole band and avoid 4.8-5.9 GHz (Whole Band System) Tewfik/Saberinia, U. of MN

7. 31 31 31 30 30 30 1 1 1 0 0 0 Frequency Hopping for Lower Band System f(GHz) 4.75 4.2 3.65 3.1 0 1.81 3.6364 5.4545 t(ns) Tewfik/Saberinia, U. of MN

8. 31 31 31 31 31 31 31 31 30 30 30 30 30 30 30 30 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 Frequency Hopping for Whole Band System f(GHz) 9.7 5.9 4.75 3.1 0 5.45 t(ns) Tewfik/Saberinia, U. of MN

9. 23 23 23 23 23 23 22 22 22 22 22 22 1 1 1 1 1 1 0 0 0 0 0 0 An FFH-UWB-OFDM Block f(GHz) 4.75 4.2 3.65 3.1 • Repeat this block every T=12.8ns N=32 times 0 5.45 12.8 t(ns) Tewfik/Saberinia, U. of MN

10. Spectrum • Bandwidth=1.65GHz • Multipath resolution=0.6ns • Bandwidth=7.5GHz • Multipath resolution=0.13ns Tewfik/Saberinia, U. of MN

11. Proposed System • N=32 Subcarrier • ¾ Convolutional Channel Coding • QAM Constellation: QPSK: 110 Mbit/s 16-QAM: 220 Mbit/s 64-QAM: 480 Mbit/s Tewfik/Saberinia, U. of MN

12. Transmitter I FFT ¾ Convlution Code QAM Mapping PAM signal Interleaving X Frequency Hopping Input rate= 78.22 M sample/s Sample and Hold for Ts= 5.45 ns Tewfik/Saberinia, U. of MN

13. Receiver X LPF S -D 1 bit A/D SYNC VCO S AGC p/2 S -D 1 bit A/D X LPF exp(j..) S X P*(n) X Decision pilot Bit mapping |.|2 S Info. Bearing carrier S X P*(n) X Decision exp(j..) Tewfik/Saberinia, U. of MN

14. Link Budget Lower Band System Whole Band System Tewfik/Saberinia, U. of MN

15. BER vs SNR for CM3 Tewfik/Saberinia, U. of MN

16. BER vs SNR for CM4 Tewfik/Saberinia, U. of MN

17. Bit rate versus Distance Tewfik/Saberinia, U. of MN

18. Bit rate versus Distance Tewfik/Saberinia, U. of MN

19. Bit rate versus Distance Tewfik/Saberinia, U. of MN

20. Coexistence Tewfik/Saberinia, U. of MN

21. Multiple Piconets • Simultaneous operation achieved by proper selection of: • Different FH code (for whole band system) • Use of piconet dependent pilots • Combination of above Tewfik/Saberinia, U. of MN

22. MF Energy Detector Correlator Decision MF Energy Detector MF Pilot Assisted Demodulation Pilot r(t) Information bearing carrier pilots Information bearing carriers Tewfik/Saberinia, U. of MN

23. Transmitter Complexity and Power Consumption Tewfik/Saberinia, U. of MN

24. Receiver Complexity and Power Consumption Tewfik/Saberinia, U. of MN

25. + X(n) 1 bit quantizer + - Traditional Sigma Delta y(n) Tewfik/Saberinia, U. of MN

26. Lowpass Filtering and downsampling + 1 bit quantizer oversample - + Traditional Sigma Delta A/D X(t) Multibit X(n) Analog switched capacitor implementation Tewfik/Saberinia, U. of MN

27. + Traditional Sigma Delta D/A Analog Lowpass Filtering + X(n) 1 bit quantizer 1 bit D/A L - X(t) upsample • Higher order SD preferred: • Better noise shaping • Eliminate spurious tones Tewfik/Saberinia, U. of MN

28. N Tone Sigma Delta + X(n) 1 bit quantizer + y(n) (e.g., output of N point IFFT) - Tewfik/Saberinia, U. of MN

29. N Tone Sigma Delta “Instantaneous” Frequency spectrum Filter outputs Tewfik/Saberinia, U. of MN

30. Conclusion • FFH-UWB-OFDM provides a compromise between pure OFDM and Multi-band UWB • It avoids Rake type receiver with reasonable size FFT-IFFT • Low complexity transmitter and receiver structures possible Tewfik/Saberinia, U. of MN