1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [Chaotic Pulse Based Communication System Proposal]
Date Submitted: [4 January, 2005]
Source: [Hyung Soo Lee (1), Cheol Hyo Lee (1), Dong Jo Park (2), Dan Keun Sung (2), Sung Yoon Jung (2), Chang Yong 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: [The Chaotic Communication System is proposed for the alternative PHY for a]
Purpose: [This submission is in response to the committee’s request to submit the proposal enabled by an alternate TG4a PHY]
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

2. CFP Presentation for IEEE 802.15.4a Alternative PHY
Chaotic Pulse Based Communication System Proposal
Electronics and Telecommunications Research Institute (ETRI)
Korea Advanced Institute of Science and Technologies (KAIST)
Handong Global University (HGU)
Republic of Korea

3. Contents Band Plan Chaotic Pulse PHY Layer Proposal System Performance
Simultaneously Operating Piconets (SOPs)
Link Budget & Sensitivity
Ranging

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

5. Chaotic Pulse Large base signal [base=2*bandwidth*duration]
Flexible bandwidth and signal duration
Low cost implementation

6. Modulation Scheme Multi-coded Pulse Position Modulation (MC- PPM)
It is power efficient scheme
It has inherent coding gain due to orthogonal multi- codes
It can support wide pulse spacing in same data rate condition
Less multipath interference between pulses
Good for non-coherent energy detection
No dynamic threshold problem
Disadvantage in On-Off Keying (OOK) based on non-coherent energy detection

7. Multi-Coded PPM (MC-PPM)
Operation example (L=3, Ns=4)
* Ref : a-multi-coded-bi-orthogonal-ppm-mc-bppm-based-impulse-radio-technology
Data block
( L bits )
Ex. L=3
Orthogonal code set
( Code Length : Ns )
Ex. Ns=4
Multi-coded symbol
( Code rate : L/Ns )
Ex. Code rate = 3/4 1 -1 -3
Modulation
MC-PPM Signal : 1 -3 1 1

8. Data Frame Structure Frame structure of PPDU
1 data block (L data) interval of PSDU :
: # of Repetitions
: Orthogonal Code length
: Position number for MC-PPM
...
Preamble
SFD
PHR
PSDU 4 1 1 32
: # 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

9. Transceiver Architecture
Transmitter
Receiver
Data Modulator
MC-PPM
Channel
Data Encoder
Orthogonal
Multi-code
Data
Pulse
Generator
Data Decoder
Orthogonal
Multi-code
Data
DeModulator
MC-PPM
Energy
Detector
Location

10. PHY-SAP Data Rates
Flexible data rates can be supported according to several design parameter (Tm, L, Ns, Nr, Tg) Tp Tm L Ns Nr Tg
Data
Rate
20ns
200ns 1 16
128
0ns
1.190 kbps 3
228 kbps 8
457 kbps
2.44 Mbps

11. Data Throughput ∙∙∙∙ Transmission time (ttx) & Data throughput (Rth)
LIFS
tACK
tlong_frame
tACK_frame
∙∙∙∙
ttx
Transmission time (ttx) & Data throughput (Rth)
For L=3, Ns=8, Nr=1,Tg=0ns (457kbps)
ttx = tlong_frame + tACK + tACK_frame + LIFS
= u u u u = 913 u
Rth = 32×8 / 913u ≈ kbps
( Nominal throughput based on 32 bytes payload )
For L=3, Ns=16, Nr=1,Tg=0ns (228kbps)
= u u u u = u
Rth = 32×8 / u ≈ kbps

12. Comments on 1kbps PHY-SAP Data Rate
Burst Transmission Scheme
<< Example >>
L=3, Ns=8, Nr=1,Tg=0ns
(457kbps)
L=3, Ns=16, Nr=1,Tg=0ns
(228kbps)
32*8/3
Data Blocks
1 Packet Time Duration

13. Signal Acquisition Energy detection based acquisition
Acquisition should be performed in order to make synchronization and demodulate data
Procedure
If the output of energy detector exceeds the threshold level, we think that the signal is acquired.
Threshold level for acquisition
Determined relative to estimated noise level

14. Synchronization Non-coherent Synchronization Procedure
Assume Nint square-law integrator
Divide Tm time into total Nint time slots
(each time slot contains Tm / Nint time)
preamble
preamble
t_s : sync. starting point
t_sync : exact sync. point

15. Synchronization Non-coherent Synchronization Procedure
The output value of n-th square-law integrator
Estimated synchronization point

16. MC-PPM Performance : AWGN
BER & PER
L=3, Ns=8,Nr=1 (457kbps PHY-SAP data rate)

17. MC-PPM Performance : 4a Channel Models
BER & PER
L=3, Ns=8,Nr=1

18. Acquisition & Synchronization Parameters
System Parameters
Chaotic Pulse [BW=1.8GHz(3.1G-4.9GHz), Tp=20ns]
Preamble Length
4 bytes (32 preamble symbols)
Tm=200ns, Ts=100ns (5 chaotic pulses of duration 20ns)
Preamble Time Duration = 32 symbols*200ns=6.4us
Num. of Integrator (Nint) = 10
Assume that only 5 Integrator are implemented in HW
Actual Preamble Length = 32 Symbols/(Nint/5)=16 Symbols
Sync. Resolution Range = [-10ns, 10ns]
Threshold level for acquisition
Determined relative to the estimated noise level

19. Acquisition Performance : AWGN
Comments
Acquisition performance is dependent on threshold level
Env.
Dist.
Miss Detection Probability
(%)
10m
≈0%
30m
0.1%

20. Synchronization Performance
Comments
Signal acquisition is assumed
Performance depends on Sync. Resolution Range
Env.
Dist.
AWGN
Industrial NLOS
(CM8)
Residential LOS
(CM1)
Outdoor LOS
(CM5)
10m
99%
74%
30m
72%
73%

21. SOPs Time Division Operating bandwidth Configuration of SOPs
GHz can be fully used (Chaotic pulse)
Configuration of SOPs
Self configuration of SOPs is possible
Piconet #1
Active
Inactive
Piconet #2
Piconet #3

22. Self Configuration of SOP
Passive Scan
Repeat scaning one channel ( GHz)
Usage
Starting a new piconet (FFD)
Association (FFD or RFD)

23. Link Budget & Sensitivity
Parameter
(mandatory)
Value at d=30m
Value at d=10m
peak payload bit rate
(457kb/s) [ L=3,Ns=8,Nr=1]
Average Tx power
-8.75 (dBm)
Tx antenna gain
0 (dBi)
geometric center frequency of waveform
3.90 (GHz)
Path loss at 1 meter
44.5dB
Path loss at d m
29.54 dB at d =30m
20 dB at d =10m
Rx antenna gain
Rx power
(dBm)
(dBm)
Average noise power per bit
(dBm)
Rx Noise Figure
7 (dB)
-110.4(dBm)
Minimum Eb/N0 (S) [Ep/N0]
20 (dB)
Implementation Loss (I)
5 (dB)
Link Margin
2.85(dB)
12.39(dB)
Proposed Min. Rx Sensitivity Level
-85.4(dBm)

24. Ranging Scheme TOA/TWR (Two Way Ranging) Measurement of Tround_trip
Packet 1
Node 1
Node 2 t1 t0 t2 t3
Tprocessing time
Tpropagation2
Packet 2
Tpropagation1
Tround trip

25. Ranging Algorithm Procedure (Algorithm)
Potential lock point (peak)
length of search region
signal leading edge
threshold level
envelope detector output
search for the 1st level-crossing point
time (ns)
Search for the 1st level-crossing point at the threshold level in negative direction from the initial lock point
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

26. Ranging Performance Performance 802.15.4a channel (cm4) Single user
No narrowband interference
Pulse width = 2ns
Considering one 2ns pulse integrator
Pulse repetition period = 200ns
Length of search region = 40ns
Threshold level was determined relative to noise floor