Transcript 15-04-0615-00-004a-keri.ppt
November 2004 doc.: IEEE 802.15-04-0615-00-004a Project: IEEE P802.15 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)+82-31-420 6183, (2)+82-2-820-0632, (3)+82-31-753-2533], FAX: [(1)82-31-420 6183, (2)82-2 821-7653, (3)+82-31-753-2532], E-Mail:[(1)[email protected], (2)[email protected], (3)hijeon@kyung won.ac.kr]
Re:
[]
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.
Submission Slide 1
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
November 2004 doc.: IEEE 802.15-04-0615-00-004a
TDOA/TWR Positioning and Ranging Techniques Based on Noncoherent OOK PHY
KERI-SSU-KWU Republic of Korea
Slide 2
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
Submission
November 2004 doc.: IEEE 802.15-04-0615-00-004a
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
Submission Slide 3
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
November 2004 doc.: IEEE 802.15-04-0615-00-004a
Proposal Overview(1)
•
Motivation of proposal
– To satisfy IEEE 802.15.4a 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
Submission Slide 4
November 2004 doc.: IEEE 802.15-04-0615-00-004a
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
Slide 5
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
Submission
November 2004 doc.: IEEE 802.15-04-0615-00-004a
Proposed Noncoherent OOK UWB System
Input Bit Sequence UWB Transmitter Data Repetition OOK Modulation
Pulse Generator
Calibration Mode Threshold Control Noise Measuring Timing Mode Coarse Pulse Position Estimation Operation Mode Receiving Data Gathering Multipath Combining Decision Stage Output Bit Sequence UWB Receiver
Submission Slide 6 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)
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
November 2004 doc.: IEEE 802.15-04-0615-00-004a
Pulse Repetition Based on Edge Triggering
Bit Sequence (input data)
Data Repetition (R=2)
Modulation ( positive pulse) Modulation ( negative pulse) Modulation ( both pulses)
Pulse repetition for data transmission Transmission Interval 1 0 1
Bit Sequence Repetition (R=4) Modulation ( positive pulse) 1 Repetition (R=8) 1
★
OOK modulation can be easily implemented by generating UWB pulse based on edge triggering
Submission Slide 7
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
November 2004 doc.: IEEE 802.15-04-0615-00-004a
Proposed Three Modes in the Receiver
Signal processing in three modes
Calibration Mode
Noise Only (No Data)
Timing Mode
Transmission Interval Preamble Signal
Operation Mode (R=2)
Receiving Data Gathering
“
1
” “
1
” “
0
”
Multipath Combining
Submission
Noise Power Level Measurement by Buffering & Averaging Threshold Reset for Bit Decision Coarse Estimation of Pulse Position & Peak Sample Position
Slide 8
Demodulation of the Received Signal Based on Power Detection Final Bit Decision by Multipath Combining & Receiving Data Gathering K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
November 2004 doc.: IEEE 802.15-04-0615-00-004a
More Details in the Operation Mode (1)
Operation mode description Received Signal Signal Power Caculation Buffer (w.r.t. multipath combining & pulse repetition)
Z
T
Decision Stage
• Decision statistics
Simple
Z
N s
1
N m
1
P
• • •
P N s N m
: Number of pulse repetitions per data bit : Number of multipath components for combining
Data Output
Slide 9
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
Submission
November 2004 doc.: IEEE 802.15-04-0615-00-004a
More Details in the Operation Mode (2)
• Threshold value for bit decision (no pulse repetition & no multipath combining)
T
.1
2
P n
• .1
: Parameter relative to the average power and power variance of the first path •
P n
: Noise power measured by noise calibration mode • Threshold value (only pulse repetition)
T
N s
.1
2
P n
• Threshold value (pulse repetition & multipath combining)
T
N s
k N m
1 .
k
2
P n
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
Submission Slide 10
November 2004 doc.: IEEE 802.15-04-0615-00-004a
•
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 Transmitted packets Received packets
TOF : Time Of Flight RTT : Round Trip Time SHR : Synchronization Header
Reference Time
But, High Complexity
A SHR Payload RTT TOF SHR Payload SHR Payload B C SHR Payload TOF AB SHR TOF AC TDOA BC
Synchronous Ranging
Payload Submission Slide 11 TOF SHR Payload SHR Payload k Pre-determined delay time(T) TOF = (RTT-2k-T)/2
Asynchronous Ranging K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
November 2004 doc.: IEEE 802.15-04-0615-00-004a
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 P_FFD3 P_FFD2 TOA 24 TOA 34 RFD PAN coordinator TOA 14 PU P_FFD : Positioning Full Function Device RFD : Reduced Function Device Benefits P_FFD1 It does not need pre-synchronization among the devices -
Positioning in mobile environment is partly accomplished
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
Submission Slide 12
November 2004 doc.: IEEE 802.15-04-0615-00-004a
Process of Proposed Positioning Scheme
Submission Slide 13
TOA measurement K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
November 2004 doc.: IEEE 802.15-04-0615-00-004a
More Details for obtaining TDOAs
• Distances among the positioning FFDs are calculated from RTT measurements and known time interval T
RTT 12 = T + 2T 12 RTT 23 = T + 2T 23 RTT 13 = T 12 + 2T + T 23 + T 13 T 12 = (RTT 12 – T)/2 T 23 = (RTT 23 – T)/2 T 13 = (RTT 13 – T 12 – T 23 – 2T)
• Using observed RTT measurements and calculated distances, TOAs/TDOAs are updated
RTT 34 = T 34 + T + T 34 RTT 24 = T 23 + T + T 34 + T + T 24 RTT 14 = T 12 + T + T 23 + T + T 34 + T + T 14 TOA 34 = (RTT 34 - T)/2 TOA 24 = (RTT 24 - T 23 - TOA 34 - 2T) TOA 14 = (RTT 14 - T 12 - T 23 - TOA 34 - 3T) TDOA 12 = TOA 14 – TOA 24 TDOA 23 = TOA 24 – TOA 34
Slide 14
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
Submission
November 2004 doc.: IEEE 802.15-04-0615-00-004a
R
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 A TOA Tag_A TDOA A_B B Tag TOA Tag_B TOA Tag_C C TDOA B_C (
TOA i
TOA j
) (
X i
Slide 15
x
) 2 (
Y i
y
) 2 (
X j
x
) 2 (
Y j
y
) 2
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
Submission
November 2004 doc.: IEEE 802.15-04-0615-00-004a
Case 1
Case 2
Submission
Positioning Scenario Overview
Cluster 1 PAN Coordinator FFD RFD Positioning FFD(P_FFD) Cluster 1
• • Slide 16
Using static reference nodes relatively large scaled cluster :
– Power control is required – Power consumption increases
in
– All devices in cluster must be in inactive data transmission mode –
Using static and mobile nodes overlapped small scaled sub clusters : in
– Sequential positioning is executed in each sub-cluster – Low power consumption – Associated sub-cluster in positioning mode should be in inactive data transmission mode
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
November 2004 doc.: IEEE 802.15-04-0615-00-004a
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 PAN coordinator P_FFD1 P_FFD2 P_FFD3 측위용 FFD1 FDD RFD2 RFD RFD1 PAN coordinator Broadcasting to all P_FFDs 측위 용 FFD2 측위 용 FFD3 RFD3 S_addr.
PAN_co.
D_addr.
P_FFD1 P_addr.
P_FFD1 P_FFD2 P_FFD3 T_addr.
T_RFD1 Submission S_addr.
P_FFD1 D_addr.
P_FFD2 P_addr.
P_FFD2 P_FFD3 T_RFD1 T_addr.
T_RFD1 S_addr.
P_FFD2 D_addr.
P_FFD3 P_addr.
P_FFD3 T_RFD1 T_addr.
T_RFD1 S_addr.
P_FFD3 D_addr.
T_RFD1 P_addr.
T_RFD1 S_addr.
T_RFD1 S_addr. : Source Address D_addr. : Destination Address P_addr. : Positioning Address T_addr. : Target Address
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
Slide 17
November 2004 doc.: IEEE 802.15-04-0615-00-004a
Positioning Scenario for Cluster-tree Topology
Cluster-tree topology FFD1 addition P_FFD3 PAN coordinator P_addr.
P_FFD3 P_FFD1 N_addr.
FFD0 FFD1 RFD6 N_P_addr.
P_FFD2 P_FFD1 re-arragement S_addr.
PAN_co.
D_addr.
P_FFD1 P_addr.
P_FFD1 P_FFD2 P_FFD3 T_addr.
T_RFD5 Submission S_addr.
P_FFD1 D_addr.
P_FFD2 P_addr.
P_FFD2 P_FFD3 T_addr.
T_RFD5 P_FFD2 S_addr.
P_FFD2 D_addr.
P_FFD3 P_addr.
P_FFD3 T_addr.
T_RFD5 Slide 18 RFD2 RFD4 RFD1 RFD0 RFD3 P_FFD1 PAN coordinator RFD7 FFD0 FFD1 P_FFD3 RFD5 P_FFD2 RFD6 RFD1 RFD3 FFD1 FFD0 RFD4 RFD2 FFD2 P_FFD3 S_addr.
P_FFD3 D_addr.
T_RFD5 T_addr.
T_RFD5 RFD Broadcasting to all P_FFDs S_addr.
T_RFD5 S_addr. : Source Address D_addr. : Destination Address P_addr. : Positioning Address T_addr. : Target Address N_addr. : Neighbor Address N_P_addr. : Neighbor Positioning Address
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
November 2004 doc.: IEEE 802.15-04-0615-00-004a
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 Frame control 1 Sequence number MHR 0/4/8 Addressing fields command frame identifier variable Positioning parameter MAC payload Command payload MFR K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
Submission Slide 19
2 FCS
November 2004 doc.: IEEE 802.15-04-0615-00-004a
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 :
m
/ sec] 3.333 [nsec] – Required clock speed
High Cost !
1 3.333 [nsec] 300 [
MHz
] ★
Fast ADC clock speed in the receiver is also required for
Submission
noncoherent power detection based OOK reception
Slide 20
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
November 2004 doc.: IEEE 802.15-04-0615-00-004a
Window #1 Window #2 Window #3 Window #99 Window #100
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 •
T
: Target clock speed
T
N W
W
• • : Number of signal processing windows : Window clock speed 100 pulse (333.333 nsec) 100 pulse (333.333 nsec) 3.333 nsec
Only 3 MHz is required !!!
–
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
K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon
Submission Slide 21