1. November 2004
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [TDOA/TWR Positioning and Ranging Techniques Based on Noncoherent OOK PHY]
Date Submitted: [09 NOV, 2004]
Source: [Kwan-Ho Kim(1), Sungsoo Choi(1), Youngjin Park(1), Hui-Myoung Oh(1), Yo-Ahn Shin(2), Wonchul Lee(2), and Ho-In Jeon(3)] Company: [(1)Korea Electrotechnology Research Institute(KERI), (2)Soongsil University(SSU), and (3)Kyoungwon University(KWU)]
Address: [(1)665-4, Naeson 2-dong, Euiwang-City, Kyunggi-do,Republic of Korea (2) 1-1, Sangdo-5-dong, Dongjak-Gu, Seoul, Republic of Korea (3)San 65, Bok-Jeong-dong, Seongnam, Republic of Korea]
Voice:[(1) , (2) , (3) ], FAX: [(1) , (2) , (3) ], won.ac.kr]
Re: []
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 P
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

2. KERI-SSU-KWU Republic of Korea
November 2004
TDOA/TWR Positioning and Ranging Techniques Based on Noncoherent OOK PHY
KERI-SSU-KWU
Republic of Korea
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

3. doc.: IEEE 802.15-<doc#>
<month year>
doc.: IEEE <doc#>
November 2004
Contents
Noncoherent OOK UWB transceiver with power detection
Three modes in the receiver for system performance improvement
Asynchronous ranging by round trip time
Positioning based on sequential relay transmission
Positioning scenarios according to network topologies
Parallel window bank for power detection & ranging accuracy improvement
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
<author>, <company>

4. Proposal Overview(1) Motivation of proposal
November 2004
Proposal Overview(1)
Motivation of proposal
To satisfy IEEE a technical requirements, it is essential that low power consumption in the UWB system level as well as link level must be achieved
Conventional coherent UWB system based on correlator in the receiver can provide fairly good performance
However, coherent UWB system is very sensitive to the signal synchronization, and the additional pulse generator is required in the receiver
Thus, this system may increase the implementation complexity, and consequently power consumption and system cost
To meet low power and low cost requirement, we propose UWB system with OOK (On-Off Keying) modulation and noncoherent detection
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

5. Proposal Overview(2) Pros & cons
November 2004
Proposal Overview(2)
Pros & cons
In the proposed UWB system, unlike the conventional coherent UWB system, the signal demodulation is performed by simply comparing the received signal power with detection threshold
It can significantly relieve the strict synchronization requirement in the receiver and also provide with simplified transceiver structure with the minimal power and cost demand, since pulse generator is omitted
However, the noncoherent OOK UWB system may yield degraded
Bit Error Rate (BER) performance
Performance improvement for the noncoherent
OOK UWB system is essential
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

6. Proposed Noncoherent OOK UWB System
November 2004
Proposed Noncoherent OOK UWB System
Non-coherent OOK UWB system
based on noise power calibration
and signal power detection
Data repetition and multipath
combining for performance
improvement
Three modes in the receiver for
compensation of performance
degradation
(calibration/timing/operation)
UWB Transmitter
Pulse
Generator
Input Bit
Data
OOK
Sequence
Repetition
Modulation
Calibration Mode ( C
Threshold
Noise a i l
Control
Measuring b a r t o i n M
Timing Mode / o T d i e m S
Coarse Pulse Position Estimation n i w g t i / c
Operation Mode O h p e P r o a
Receiving w t
Multipath o i
Data e
Combining r n )
Gathering D e t c e t o i
Decision
Output Bit n
Stage
Sequence
UWB Receiver
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

7. Pulse Repetition Based on Edge Triggering
November 2004
Pulse Repetition Based on Edge Triggering
Pulse repetition for data transmission
OOK modulation can be easily implemented by generating UWB pulse based on edge triggering
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

8. Proposed Three Modes in the Receiver
November 2004
Proposed Three Modes in the Receiver
Signal processing in three modes
Calibration Mode
Timing Mode
Operation Mode (R=2)
Receiving Data
Preamble
Gathering
Transmission
Signal
Interval
“1”
“1”
“0”
Multipath
Noise Only (No Data)
Combining
Noise Power Level
Coarse Estimation
Demodulation of the
Measurement by
of Pulse Position &
Received Signal Based
Buffering & Averaging
Peak Sample Position
on Power Detection
Final Bit Decision by
Threshold Reset
Multipath Combining &
for Bit Decision
Receiving Data Gathering
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

9. More Details in the Operation Mode (1)
November 2004
More Details in the Operation Mode (1)
Operation mode description
Decision statistics
: Number of pulse repetitions per data bit
: Number of multipath components for combining
: Received signal power corresponding to the ’th path
of the ’th transmitted pulse
Simple
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

10. More Details in the Operation Mode (2)
November 2004
More Details in the Operation Mode (2)
Threshold value for bit decision (no pulse repetition & no multipath combining)
: Parameter relative to the average power and power
variance of the first path
: Noise power measured by noise calibration mode
Threshold value (pulse repetition & multipath combining)
Threshold value (only pulse repetition)
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

11. Asynchronous Ranging Scheme
November 2004
Asynchronous Ranging Scheme
Synchronous ranging
One way ranging
Simple TOA/TDOA measurement
Universal external clock
Asynchronous ranging
Two way ranging
TOA/TDOA measurement by RTTs
Half-duplex type of signal exchange
TOF : Time Of Flight
RTT : Round Trip Time
SHR : Synchronization Header
But, High
Complexity
Synchronous Ranging
Asynchronous Ranging
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

12. Proposed Positioning Scheme
November 2004
Proposed Positioning Scheme
Features - Sequential two-way ranging is executed via relay transmissions - PAN coordinator manages the overall schedule for positioning - Inactive mode processing is required along the positioning - PAN coordinator may transfer all sorts of information such as observed - TDOAs to a processing unit (PU) for position calculation Benefits - It does not need pre-synchronization among the devices - Positioning in mobile environment is partly accomplished
P_FFD3
P_FFD2
TOA 24
TOA 34
RFD
PAN
coordinator
TOA PU 14
P_FFD : Positioning Full Function Device
RFD : Reduced Function Device
P_FFD1
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

13. Process of Proposed Positioning Scheme
November 2004
Process of Proposed Positioning Scheme
TOA measurement
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

14. More Details for obtaining TDOAs
November 2004
More Details for obtaining TDOAs
Distances among the positioning FFDs are calculated from RTT measurements and known time interval T
Using observed RTT measurements and calculated distances, TOAs/TDOAs are updated
RTT12 = T + 2T12
RTT23 = T + 2T23
RTT13 = T12 + 2T + T23 + T13
T12 = (RTT12 – T)/2
T23 = (RTT23 – T)/2
T13 = (RTT13 – T12 – T23 – 2T)
RTT34 = T34 + T + T34
TOA34 = (RTT34 - T)/2
RTT24 = T23 + T + T34 + T + T24
TOA24 = (RTT24 - T23 - TOA34 - 2T)
RTT14 = T12 + T + T23 + T + T34 + T + T14
TOA14 = (RTT14 - T12 - T23 - TOA34 - 3T)
TDOA12 = TOA14 – TOA24
TDOA23 = TOA24 – TOA34
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

15. Position Calculation using TDOAs
November 2004
Position Calculation using TDOAs
The range difference measurement defines a hyperboloid of constant range difference
When multiple range difference measurements are obtained, producing multiple hyperboloids, the position location of the device is at the intersection among the hyperboloids
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

16. Positioning Scenario Overview
November 2004
Positioning Scenario Overview
Using static reference nodes in relatively large scaled cluster :
Power control is required
Power consumption increases
All devices in cluster must be in inactive data transmission mode
Using static and mobile nodes in overlapped small scaled sub-clusters :
Sequential positioning is executed in each sub-cluster
Low power consumption
Associated sub-cluster in positioning mode should be in inactive data transmission mode
Case 1
Cluster 1
PAN Coordinator
FFD
RFD
Positioning FFD(P_FFD)
Case 2
Cluster 1
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

17. Positioning Scenario for Star topology
November 2004
Positioning Scenario for Star topology
Star topology
PAN coordinator activated mode
Positioning all devices
Re-alignment of positioning FFD’s list is not required
Target device activated mode
Positioning is requested from some device
Re-alignment of positioning FFD’s list is required
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

18. Positioning Scenario for Cluster-tree Topology
November 2004
Positioning Scenario for Cluster-tree Topology
Cluster-tree topology
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

19. Modifications of MAC Common Frame
November 2004
Modifications of MAC Common Frame
Features
Frame control field
frame type : positioning (new addition)
Command frame identifier field
Positioning request/response (new addition)
Positioning parameter information field
Absolute coordinates of positioning FFDs
POS range
List of positioning FFDs and target devices
Power control
Pre-determined processing time (T)
Octets : 2 1
0/4/8
variable 2
Frame
control
Sequence
number
Addressing
fields
command frame identifier
Positioning parameter
Command
payload
FCS
MHR
MAC payload
MFR
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

20. Signal Processing for Accuracy Improvement (1)
November 2004
Signal Processing for Accuracy Improvement (1)
Technical requirement for positioning
“It can be related to precise (tens of centimeters) localization in some cases, but is generally limited to about one meter ”
Parameters for technical requirement
Pulse duration :
Required clock speed
High Cost !
Fast ADC clock speed in the receiver is also required for
noncoherent power detection based OOK reception
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

21. Signal Processing for Accuracy Improvement (2)
November 2004
Signal Processing for Accuracy Improvement (2)
Proposed parallel window bank
Fast clock can be implemented by using parallel signal processing windows with low clock speed
: Target clock speed
: Number of signal processing windows
: Window clock speed
Example
Pulse duration is 3.33 nsec
Target speed is 300 MHz
Each signal processing
window has 3 MHz speed
Number of windows is 100
Only 3 MHz is
required !!!
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon