Locating in Fingerprint Space: Wireless Indoor

Review & PResentation

Locating in Fingerprint Space: Wireless Indoor Localization with Little Human Intervention Zheng Yang, Chenshu Wu, and Yunhao Liu Tsinghua University

outline LIFS

outline Background ~ Motivation ~ IPS & Site Survey Research Solution & Design Detailed Study ~ Stress-free Floor Plan ~ Fingerprint Space ~ Mapping Experimental Results Discussion Concluding Remarks

Global vs. indooR PositioninG system

vaRious indooR localization solutions

Fingerprinting-based method becomes the promising solution for ubiquitous IPS.

FinGeRPRintinG-based techniques

site suRvey

site suRvey

outline Background ~ Motivation ~ IPS & Site Survey Research Solution & Design Detailed Study ~ Stress-free Floor Plan ~ Fingerprint Space ~ Mapping Experimental Results Discussion Concluding Remarks

basic idea

basic idea

multi-dimensional scalinG

liFs desiGn

outline Background ~ Motivation ~ IPS & Site Survey Research Solution & Design Detailed Study ~ Stress-free Floor Plan ~ Fingerprint Space ~ Mapping Experimental Results Discussion Concluding Remarks

stRess-FRee FlooR Plan

stRess-FRee FlooR Plan

data collection

distance matRix

FinGeRPRint sPace constRuction

maPPinG

maPPinG Solution: Mapping corridors first, then rooms.

coRRidoR RecoGnition Build the Minimum Spanning Tree(MST) that connects all fingerprints Corridors: Fingerprints collected at corridors reside in core positions in fingerprint space, which have relatively large centrality values.

Rooms: Remove corridor points from the fingerprint space and cluster the remaining points into đ?‘˜ clusters

coRRidoR RecoGnition

ReFeRence Point extRaction Reference Point Mapping: Find keys from the doors

sPace tRansFoRmation

sPace tRansFoRmation

sPace tRansFoRmation

outline Background ~ Motivation ~ IPS & Site Survey Research Solution & Design Detailed Study ~ Stress-free Floor Plan ~ Fingerprint Space ~ Mapping Experiment Results Discussion Concluding Remarks

evaluation  They implemented LiFS on Android phones (Google Nexus S).  They conducted experiments in a typical office building in Tsinghua University.  Size of 1600m2, with 5 large rooms of 142m2, 7 small ones with different sizes and the other 4 inaccessible rooms.  Totally m= 26 APs are installed (some with known locations).

evaluation ď ą They sample the floor plan every 4đ?‘š2 and obtain 292 location points over all accessible areas. ď ą They collect 600 traces by asking 4 volunteers to walk through areas of interests for 5 hours. ď ą For each trace, record WiFi with period of about 4 seconds

PeRFoRmance

outline Background ~ Motivation ~ IPS & Site Survey Research Solution & Design Detailed Study ~ Stress-free Floor Plan ~ Fingerprint Space ~ Mapping Experimental Results Discussion Concluding Remarks

discussion

discussion

conclusion

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