Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: Multi-coded Bi-orthogonal PPM (MC-BPPM) Based Impulse Radio Technology Date Submitted: 8 Sep., 2004 Source: [Hyung Soo Lee (1), Dong Jo Park (2), Dan Keun Sung (2), Sung Yoon Jung (2), Joon Yong Lee (3)] Company: [(1) Electronics and Telecommunications Research Institute (ETRI) (2) Korea Advanced Institute of Science and Technologies (KAIST) (3) Handong Global University (HGU)] Address: [(1) 161 Gajeong-dong, Yuseong-gu, Daejeon, Republic of Korea (2) 373-1 Guseong-dong, Yuseong-gu, Daejeon, Republic of Korea (3) Heunghae-eup, Buk-gu, Pohang, Republic of Korea] Voice: [(1) +82 42 860 5625, (2) +82 42 869 5438, (3) +82 54 260 1931], FAX: [(2) +82 42 869 8038] E-Mail: [(1) hsulee@etri.re.kr, (2) syjung@kaist.ac.kr, (3) joonlee@handong.edu] Abstract: [This document proposes preliminary proposal for the IEEE 802.15.4 alternate PHY standard] Purpose: Preliminary Proposal for the IEEE802.15.4a standard 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

Multi-Coded Bi-orthogonal PPM Based Impulse Radio Technology ETRI-KAIST-HGU Republic of Korea

Contents TG 4a Alt-PHY Design Issues Band Plan Pulse Design Multi-Coded Bi-orthogonal PPM (MC-BPPM) PHY Frame Structure Transceiver Architecture Data Rate Link Budget Location Awareness

TG 4a Alt-PHY Design Issues We are focused on… Data rate scalability - Link bit rate : 1 kbps (mandatory) - Aggregate bit rate : 1 Mbps (optional) Harsh multipath environment (long delay spread) - Require a long guard time to avoid inter pulse interference (IPI) Location awareness - High / Medium / Low accuracy

Band Plan Bandwidth : Two bands - Low band (3.1 to 4.9 GHz) : Mandatory band - High band (5.825 to 10.6 GHz) Low band High band 3 4 5 6 7 8 9 10 11 3 4 5 6 7 8 9 10 11

Low Band Pulse Design : Example (1) Prolate pulse* - Pulse duration : 2.1376ns  Bandwidth : 1.8GHz *: Parr, B.; ByungLok Cho; Wallace, K.; Zhi Ding Communications Letters, IEEE , Volume: 7 , Issue: 5 , May 2003

Low Band Pulse Design : Example (2) Chaotic pulse - Large base signal (base=2*bandwidth*duration) - Flexible bandwidth and signal duration

Multi-Coded Bi-orthogonal PPM (MC-BPPM) Operation example (L=3, Ns=4, Nr=1, Tg=0 ns) Multi-coded symbol ( Code rate : L/Ns ) Ex. Code rate = 3/4 1 -1 -3 Data block ( L bits ) Ex. L=3 Orthogonal code set ( Code Length : Ns ) Ex. Ns=4 Modulation Bi-orthogonal PPM : 1 -3 1 1

: Position number for BPPM PHY Frame Structure Frame structure of PPDU (example) Preamble SFD PHR PSDU : # of Repetitions : Code length : Position number for BPPM : # of bits per data block : Orthogonal code length : # of repetitions : Pulse bin width (duration) : Total transmit time duration of a data block : Guard time for processing delay : Multi-coded chip duration : Multi-coded symbol duration

Transceiver Architecture Transmitter Receiver Data Modulator Bi-phase PPM Channel Data Encoder Orthogonal Multi-code Data Pulse Generator Data Decoder Orthogonal Multi-code Data DeModulator Bi-phase PPM Pulse Generator Location Detector

Data Rate Low band modes (example) Tm L Ns Nr Data Rate Target Data Rate 200ns 1 32 128 1.220 kbps 1 kbps 16 19.53 kbps 20 kbps 3 4 117.19 kbps 100 kbps 5 8 1.042 Mbps 1 Mbps

Link Budget : Example Bandwidth : 1.8GHz MC-BPPM 1% PER Parameter Unit Value 1. Information data rate kbps 1000 1 2. Distance (d) m 30 3. Average TX power dBm -8.75 -35.75 4. Tx antenna gain dBi 5. Geometric center freq. GHz 4 6. Path loss at 1 m dB 44.5 7. Path loss at d m 29.5 8. Rx antenna gain -3 9. Rx power -85.75 -112.75 10. Average noise power per bit -114 -144 11. Rx noise figure (NF) 6.6 12. Average noise power per bit -107.4 -137.4 13. Required Eb/No 14 11.5 14. Implementation Loss 2.5 15. Rx. Sensitivity Level -90.9 -123.4 16. Link Margin 5.15 10.65 Bandwidth : 1.8GHz MC-BPPM 1% PER (32 Octets/Packet, 200 Packets)

Location Awareness : Ranging Accuracy Parameter Unit Value Information data rate Kbps 1 L - Ns 32 Nr 128 Tm ns 200 Number of packets transmitted for range estimation 2 Peak SNR dB 2.047 Pulse Prolate Pulse (BW:1.8GHz) Channel mode CM4 Sample interval 0.2 Search region duration (Tsearch) 40 # of integration (Nint) 32 x 128 x 2 / 40 x 0.2 = 40 RMS accuracy of ToA estimation 1.19 RMS accuracy of ranging m 0.36

Conclusions Multi-Coded Bi-orthogonal PPM Candidates for UWB Pulses Prolate pulse / Chaotic pulse Time-diversity gain Data rate scalability Wide pulse bin width Reduced duty cycle Mitigated Inter bin Interference (IBI)

Back-Up Slides

Achievable Data Rate (Link Capacity) Parameter Setting Tm=2.1376ns(=Tw) , Tg=0ns / Ns=4 & 8 , Nr=1 Comparison with M-ary BPPM, BPSK Same Tx. pulse power per bit (Ns : repetition code length for BPPM, BPSK)

Pulse Bin Width (Tm) Pulse bin width vs. link capacity Higher link capacity Lower data transmission time Wide pulse bin width is possible!! Multipath immunity => Low Rx. complexity ( No equalizer )

Pulse Bin Width (Tm) Pulse bin width comparison Comparison with (M-ary) BPPM & BPSK Same link capacity condition, same Tx. pulse power per bit EbNo (dB) (L,Ns) 2 4 6 8 10 Avg. (1,4) BPPM 0.995 0.998 1.005 1.003 1.000 BPSK 1.001 0.999 (3,4) 0.604 0.606 0.587 0.554 0.521 0.505 0.563 0.760 0.769 0.755 0.723 0.691 0.672 0.728 (1,8) 1.002 (3,8) 0.580 0.584 0.573 0.548 0.520 0.552 0.766 0.768 0.752 0.722 (5,8) 0.211 0.222 0.225 0.214 0.199 0.190 0.210 0.742 0.745 0.677 0.633 0.609 0.688

Pulse Bin Width (Tm) Example Let L=5, Ns=8 Lower pulse duty cycle than M-ary BPPM & BPSK

Pulse Bin Width (Tm) Example Let L=5, Ns=8 < TG 3a CM 4 > More multipath Immunity than (M-ary) BPPM & BPSK!! No additional complexity to mitigate IBI!! < TG 3a CM 4 >

Location Awareness : Scenarios Sensor network by UWB UWB tag UWB tag UWB tag Criteria Mobility of Nodes - Stationary, movable, or mobile Density of Nodes - Dense or sparse Mobility of Reference Nodes Position Accuracy - Low / Medium / High accuracy Wake up “Yellow shirts”. “Information” UWB tag UWB tag UWB tag UWB tag UWB tag UWB tag Nodes are stationary Nodes are mobile *Source : IEEE 15-03-0537-00-004a

Location Awareness : ToA Measurement of Direct Path Signal Initial lock point Serial search by sampling & integration (Search for the 1st level-crossing point) Length of search region Correlator output Threshold ToA of direct path Search by sampling over multiple-pulse transmissions References: Joon-Yong Lee and Robert A. Scholtz, "Ranging in a dense multipath environment using an UWB radio link" , IEEE Journal on Selected Areas in Communications, vol.20, no.9, pp.1677 - 1683, Dec. 2002 Robert A. Scholtz and Joon-Yong Lee, "Problems in modeling UWB channels", 36'th Asilomar Conference on Signals, Systems & Computers, Nov. 2002