doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 1 Project: IEEE P 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 EECS Bldg.,Minneapolis, MN 55455] Voice:[ ], FAX: [ ], 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 a task group.] Notice:This document has been prepared to assist the IEEE P 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 P

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 2 Multicarrier-UWB A.H. Tewfik and E. Saberinia University of Minnesota

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 3 Overview Unified view of UWB Multicarrier-UWB Proposed system N-tone sigma-delta modulators Self-evaluation

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 4 Unified View of UWB General form Special cases –TM-UWB –DS-UWB –MC-UWB u Tp (t) TpTp x pulse train Info. signal

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 5 Unified View of UWB Advantageous to view p(t) as: p(t)= [pulse train]x[spreading sequence] x pulse train Info. signal x FH or DS Spreading sequence

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 6 Desirable Attributes Replication in time and frequency domains needed for reliable communications Poor spectral use –Spectral gaps –Spectral shaping due to S(f) x pulse train Info. signal Shaping due to s(t) Baseband signal replicas around Fourier components at f k = k/T u(t) NT 1/NT 1/T

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 7 Desirable Attributes Fill the gaps between the spectral lines x pulse train Info. signal Shaping due to s(t) Fill the gaps between spectral lines at f k = k/T u(t) NT 1/NT 1/T

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 8 Desirable Attributes MC-UWB Matched filter channel

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 9 Desirable Attributes Ambiguity function of p(t) Would like:  p ( ,f)  0 except for the origin ( ,f) =(0,0)

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 10 Multicarrier UWB Elemental signal c(n): Costas’ sequence Time resolution: T c /N Frequency resolution: 1/NT

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 11 Multicarrier UWB Advantages –Good time and frequency resolution –Time resolution decoupled from elementary pulse duration inter-pulse separation  More flexibility for design

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 12 Design Approach Select elementary pulse duration based on peak power and pulse length limitations and desired sidelobe behavior in frequency domain Select inter-pulse separation and number of pulse based on channel spread and average power limitation Select T C to fill available bandwidth

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 13 General System K tone IFFT 1 bit D/A x Modulation: Carrier + FH spreading data MC-UWB signal Combined Coding And Modulation Information bearing carriers + pilots

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 14 Proposed System TCM-QAM10 tone IFFT 1 bit D/A x Modulation: Carrier + FH spreading data MC-UWB signal System parameters: –N=30, T=9nsec, T s =1.2nsec, T c =4.1nsec –10 subcarriers for Data and Pilot with TCM 32- ary QAM

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 15 Transmitter Im( ) Re( ) N-Tone  1 bit D/A X  FH c(n) VCO N-Tone  1 bit D/A X  TCM- QAM I FF T

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 16 Proposed System Demodulator 1 bit A/D Pilot correlation 10 tone FFT Costas sequence modulated filterbank AGC Decision data 

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 17 Receiver LPF  1 bit A/D X  SYNC VCO LPF  1 bit A/D X  AGC P*(n) X X Decision Bit mapping Decision exp(j..) X X     pilot Info. Bearing carrier

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 18 Receiver LPF  1 bit A/D X  SYNC VCO LPF  1 bit A/D X  AGC P*(n) X X Channel Estimation Multi-band 10-Finger Adaptive Rake receiver DECISIOnDECISIOn exp(j..)

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 19 Link Budget

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 20 BER vs SNR for CM3

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 21 BER vs SNR for CM4

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 22 Traditional Sigma Delta + 1 bit quantizer + - X(n) y(n)

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 23 Traditional Sigma Delta D/A X(t) Multibit X(n) + 1 bit quantizer + - Lowpass Filtering and downsampling oversample Analog switched capacitor implementation

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 24 Traditional Sigma Delta D/A X(n) X(t) + 1 bit quantizer + - Analog Lowpass Filtering upsample L 1 bit D/A Higher order  preferred: –Better noise shaping –Eliminate spurious tones

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 25 N Tone Sigma Delta + 1 bit quantizer + - X(n) y(n) (e.g., output of N point IFFT)

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 26 N Tone Sigma Delta Filter outputs “Instantaneous” Frequency spectrum

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 27 N Tone Sigma Delta Average Frequency spectrum

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 28 Multiple Piconets Simultaneous operation achieved by proper selection of: –Pulse train p(t) Costas sequence c(n) Time hopping –Carrier frequencies –Use of piconet dependent pilots –Combination of above

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 29 Pilot Assisted Demodulation MF Correlator Energy Detector Decision Energy Detector Information bearing carrier Pilot r(t) pilots Information bearing carriers MF

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 30 Coexistence

doc.: IEEE Submission March 3, 2003 Tewfik/Saberinia, U. of MNSlide 31 Conclusion Multi-carrier UWB offers ability to use traditional baseband modulation schemes and achieve desired performance Implementation simplified by use of N- tone sigma-delta modulators