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doc.: IEEE 802.22-11/0078r01 Submission July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 1 Precision Geolocation in Challenging Environments Authors: Abstract This tutorial is for the IEEE 802 Plenary session on July 2011 in San Francisco The presentation describes how location techniques can improve the proposed geo-location range and accuracy for determining location in challenging environments. Notice: This Document has been prepared to assist the IEEE P802.22. 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 P802.22.
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doc.: IEEE 802.22-11/0078r1 Submission July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 2 Possible Use Cases
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doc.: IEEE 802.22-11/0078r1 Submission Rural Geo-Location July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 3 30 km Backhaul BS CPE
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doc.: IEEE 802.22-11/0078r1 Submission Outdoor Geo-Location July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 4 Geo-Locate over long distances Needs either multiple Base Stations … or a Base Station and a number of reference CPEs for which the latitude and longitude are known
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doc.: IEEE 802.22-11/0078r1 Submission Urban Corridor and Indoor Geo-Location July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 5 Geo-Locate over shorter distances Needs to operate in harsh multipath environment Either a terminal (nomadic CPE) or base station/ fixed CPE originates the ranging signal
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doc.: IEEE 802.22-11/0078r1 Submission Multiple Use Cases PUBLIC SAFETY/ MILITARY Locate/Track Personnel Search & Rescue Monitor Military Campaigns SALES & MARKETING Social Networking Location-aware Advertising Social Gaming LBS / ASSET TRACKING Warehouses Equipment & Supplies Disaster Recovery Russ Markhovsky, InvisiTrack, Inc. 6 July 2011
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doc.: IEEE 802.22-11/0078r01 Submission Integrated (Hybrid Positioning Enhancement) 400 meters 7Russ Markhovsky, InvisiTrack, Inc. GPS A-GPS Cell-ID ISM BANDS 3 meters 50 meters 300 meters 100 meters 6 meters July 2011 TVWS BANDS
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doc.: IEEE 802.22-11/0078r01 Submission Defining Core Problem July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 8
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doc.: IEEE 802.22-11/0078r01 Submission Signal Propagation - Background Signal penetration in dielectric –Loss varies as square root of wavelength Lower frequencies penetrate better than higher Example: with the same loss, 240 MHz penetrates 3.2 times further than 2.4 GHz or, at same distance, loss at 2.4 GHz is 10 dB greater. –Dispersion (multipath): inversely proportional to wavelength Objects smaller than the wavelength dont reflect; Objects larger than the wavelength, reflect and generate multipath dispersion. July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 9
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doc.: IEEE 802.22-11/0078r01 Submission White Spaces Superior Platform for Location The lower the frequency, the greater the ability to penetrate buildings and thereby improve location positioning accuracy and reliability. 512 MHz 900 MHz 2.4 GHz 5.6 GHz (UWB) Obstacle: Metal Beam Frequency Spectrum High Low 10Russ Markhovsky, InvisiTrack, Inc. July 2011 Ideal for Terrestrial Geolocation Ideal for Terrestrial Geolocation
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doc.: IEEE 802.22-11/0078r01 Submission Proposed Solutions July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 11
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doc.: IEEE 802.22-11/0078r1 Submission July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 12 With the required +/- 15 m ranging accuracy, once impact of SNR and other imperfections are taken into account, there is little room left for the actual ranging errors that are associated with ranging in a dense multipath environment in buildings/ urban corridors where multipath echoes are closely spaced Multipath Mitigation Real-time ranging signal (terrestrial positioning signal) processing algorithm (method) that mitigates multipath and delivers high accuracy using < 6 MHz of bandwidth How do you deal with complex environment location?
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doc.: IEEE 802.22-11/0078r01 Submission Multipath Mitigation July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 13
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doc.: IEEE 802.22-11/0078r01 Submission Multipath Mitigation Overview Can be easily incorporated into OFDM based wireless networks, –Employs existing wireless network signals Reference and/ or pilot signals, etc. –No changes to HW and OS Developed for indoor and challenging outdoor environments –Dense multipath environment Low computational intensity multipath mitigation algorithms –Can be executed in software by a mobile terminal Developed for fixed and mobile environment –Allows simultaneous tracking of hundreds terminals July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 14
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doc.: IEEE 802.22-11/0078r01 Submission Geolocation ranging signal is < 6 MHz BW (i.e., does not require channel bonding). The ranging signal consists of: –Pilot signals or subcarrier signals; or –A combination of pilots and subcarriers; The ranging signal subcarriers do not need to be modulated; the modulation may also be applied, for example QPSK, as long as the modulation signal is known beforehand. Solution Integration July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 15
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doc.: IEEE 802.22-11/0078r01 Submission Multipath Mitigation Processor Maps time delay to phase offset – resulting in observables sums of complex sinusoids; Uses optimized high-resolution spectrum estimation analysis methods and techniques; –Algorithms designed to separate direct path for Accurate range estimation Methods and techniques support frequency estimations (delays) that approach the Cramer-Rao Bound (CRB). July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 16
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doc.: IEEE 802.22-11/0078r01 Submission Solution Integration Can be seamlessly integrated into the current 802.22 geolocation model – uses complex channel impulse response in the frequency domain Current 802.22 Geo- location model Noise Signal New option for 802.22 Geo-location model Multipath Processor July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 17
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doc.: IEEE 802.22-11/0078r01 Submission Ranging Modes July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 18
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doc.: IEEE 802.22-11/0078r01 Submission One-way and Two-way mode ranging
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doc.: IEEE 802.22-11/0078r01 Submission Test Results July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 20
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doc.: IEEE 802.22-11/0078r01 Submission Geo-location Results Developed portable, battery-operated proof of concept: –Dimensions:3x4x2 inches –Operating frequencies:VHF (High-band) –Operating bandwidth: 5 MHz In all tests TX and RX antennas heights were between 0.5 meter to 1.5 meters from the ground. July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 21
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doc.: IEEE 802.22-11/0078r01 Submission EnvironmentRange (m)Accuracy (m), >=67% confidence Accuracy (m), >=95% confidence Comments Coaxial cables 500 (equiv)N/A0.5With multipath simulator Analog Proof of Concept Devices Outdoor 35023 Suburban setting Difficult Indoor 12548Multiple floor buildings Extreme, Indoor parking 12548 Reinforced Concrete structure July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 22 Geolocation Results
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doc.: IEEE 802.22-11/0078r01 Submission UMBC Field July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 23 Amplitude Estimate Phase Estimate
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doc.: IEEE 802.22-11/0078r01 Submission Conversion to Distance July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 24
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doc.: IEEE 802.22-11/0078r01 Submission UMBC Field July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 25
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doc.: IEEE 802.22-11/0078r01 Submission UMBC Engineering July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 26
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doc.: IEEE 802.22-11/0078r01 Submission Conversion to Distance July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 27
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doc.: IEEE 802.22-11/0078r01 Submission Result July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 28
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doc.: IEEE 802.22-11/0078r01 Submission Additional Test Results July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 29
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doc.: IEEE 802.22-11/0078r01 Submission UMBC Parking Garage July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 30
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doc.: IEEE 802.22-11/0078r01 Submission Conversion To Distance July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 31
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doc.: IEEE 802.22-11/0078r01 Submission Result July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 32
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doc.: IEEE 802.22-11/0078r01 Submission UMBC Commons July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 33
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doc.: IEEE 802.22-11/0078r01 Submission UMBC Engineering (Example 2) July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 34
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doc.: IEEE 802.22-11/0078r01 Submission Conversion to Distance July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 35
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doc.: IEEE 802.22-11/0078r01 Submission Results July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 36
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doc.: IEEE 802.22-11/0078r01 Submission UMBC Parking Garage (Example 2) July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 37
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doc.: IEEE 802.22-11/0078r01 Submission Conversion to Distance July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 38
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doc.: IEEE 802.22-11/0078r01 Submission Result July 2011 Russ Markhovsky, InvisiTrack, Inc.Slide 39
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doc.: IEEE 802.22-11/0078r1 Submission July 2011 (DRAFT) Russ Markhovsky, InvisiTrack, Inc.Slide 40 Backup Slides
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doc.: IEEE 802.22-11/0078r1 Submission Gerald Chouinard, Russ Markvosky Slide 41 Geolocation accuracy vs fine ranging accuracy For a given geolocation error, the ranging error has to be smaller because geolocation methods/ techniques can be subject to location geometry degradation. Good Geometry Bad Geometry Trilateration Triangulation Assuming that the geometry degradation amplification is 2X (on average), the required ranging accuracy is +/- 25 meters. In addition, the network device electronics propagation delays (residual delay) accuracy is assumend to be +/- 30 ns. This results in +/- 10 meters ranging error In 802.22, this residual delay needs to be measured by the manufacturer with an accuracy of at least +/-30 ns (IEEE Std 802.22-2011, subclause 7.7.7.3.4.10.) Thus the required fine ranging accuracy needs to be +/- 15 meters
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