Ultrawideband Radar Processing Using Channel information from communication HardwareIntroductionPropagationMethod 1: Multiple UsersMethod 1 PerformanceMethod 2: Single AntennaBasic CalculationsOther Methods and Future WorkUltrawideband Radar Processing Using Channel information from communication Hardware Bryan WestcottUltrawideband Radar Processing using Channel Information from Communication HardwareIntroductionMapping the physical environment with channel information, sometimes called echolocationReuse hardware and network activityApplications include: location-based services, indoor GPS, location-based security, augmented realityTwo novel methods presentedPropagationWideband signals produce clearly resolvable multipath [Hovinen, 2002]Reflection, diffraction, corner reflectionsSonar methods use directional arrays- No angle-of-arrival ambiguity- But can’t use information from multiple reflectionsMethod 1: Multiple UsersDistributed set of users Calculate all possible tangents to pairs of reflections- One self reflection, one distributedSolutions- Collinear lines are surfaces- Intersecting lines are edges- Don’t calculate for bad solutionsRefinements possible after main surfaces are found- Find corners- Find hidden surfacesNo classification of multipath requiredMethod 1 PerformanceMeasure performance, users vs. channel tapsQuality combines correct hits, false hits and complexityRepeated measurement practical for SIC [Andrews, 2004]Method 2: Single AntennaMap a room with a single antennaWith two single reflections and one double reflection, we can measure the angle between all walls and classify reflectionsCombine all angles to solve for environment- 90/180 degree walls simplify equations, allow for refinements- Otherwise more calculations, but less commonComplications include: hidden surfaces, hidden corners and diffracting edgesCan extend the solution for these situations once initial solution is foundBasic CalculationsExtension of [McKerrow, 1993]Check for bad solutionsFirst method assumes user triangulation [IEEE 802.15 TG4a]More complicated for refinements, and multiple antennas222212142222141222212422212142242222422222214224222242222424624624242412222212212212190180limits and tionssimplifica2222tan2method241688244168824288316316421methodtdd:tdd:)-ddd+-ddt+dt+(- t)+d-t^(d-aπangles)r-sr+-srt+st+(-tys)r+-s(-tx)r-sr+-srt+st+)(-tr+- ss(t)rt-rs++tts-ssr-st-tr(y)rss(t)str(tx///Other Methods and Future WorkMethod 3: single user with multiple antennas- Use channel information between all antenna- Similar to array processingFuture Work- Kalman filter to track changes without requiring complete recalculation-Analyze effect of timing
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