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Indoor Localization with a Crowdsourcing based Fingerprints Collecting. System Architecture. Key Technology. Crowdsourcing based fingerprint extraction methods Localization Algorithms based on clustering theory. Fingerprints Extraction.
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Indoor Localization with a Crowdsourcing based Fingerprints Collecting
Key Technology • Crowdsourcing based fingerprint extraction methods • Localization Algorithms based on clustering theory
Fingerprints Extraction • In crowdsourcing model, multiple users will upload fingerprints via diverse devices • Our method extract fingerprint value based on RSS probability estimation, choose the optimum value from upload samples • Kernel density estimation eliminates device diversity than Gaussian probability estimation
Fingerprints Extraction • Comparison of Gaussian and Kernel density estimation:
Fingerprints Extraction • Based on kernel density estimation, choose optimum value from multiple upload RSS samples by multiple users by diverse devices.
Localization Algorithm: MMC-KNN • MMC-KNN algorithm: find M most matched clusters, then apply KNN principle to choose out matched fingerprint • Use affinity propagation to process clustering:
Localization Algorithm: MMC-KNN • How to find out the M most matched cluster? • Consider uploaded observation’s connections and similarities with all exemplars • Apply affinity propagation again and get responsibility vector: • choose the M most matched cluster by sort this responsibility vector
Localization Algorithm: MMC-KNN • Assign a weight factor to each cluster’s fingerprints • Apply a grid window filter to filter a region which has the maximum weight, with the purpose to restrict KNN applied to a bursting region
Real-time experimental testbed • Average error distance with different matched cluster number and grid window size for Nexus-S
Real-time experimental testbed • 220 observation’s error distance statistic with best performance parameters for Nexus-S
Real-time experimental testbed • CDF of location error distance for different algorithms
Real-time experimental testbed • Comparison of different types devices’ location performance under diverse fingerprint databases