November 2004 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)yjpark@keri.re.kr, (2)yashin@e.ssu.ac.kr, (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. K. Kim, S. Choi, Y. Park, H. Oh, Y. Shin, W. Lee, and H. Jeon

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

doc.: IEEE 802.15-<doc#> <month year> doc.: IEEE 802.15-<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>

Proposal Overview(1) Motivation of proposal November 2004 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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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