1. 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) Guseong-dong, Yuseong-gu, Daejeon, Republic of Korea (3) Heunghae-eup, Buk-gu, Pohang, Republic of Korea]
Voice: [(1) , (2) , (3) ], FAX: [(2) ]
[(1) (2) (3)
Abstract: [This document proposes preliminary proposal for the IEEE alternate PHY standard]
Purpose: Preliminary Proposal for the IEEE a standard
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 P802.15

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

3. 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

4. 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

5. 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

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

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

8. 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

9. : 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

10. 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

11. 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
kbps
100 kbps 5 8
1.042 Mbps
1 Mbps

12. 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
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)

13. 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

14. 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)

15. Back-Up Slides

16. 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)

17. 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 )

18. 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

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

20. 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 >

21. 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 a

22. 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 , Dec. 2002
Robert A. Scholtz and Joon-Yong Lee, "Problems in modeling UWB channels", 36'th Asilomar Conference on Signals, Systems & Computers, Nov. 2002