Spot An accurate and efficient multi-entity device-free WLAN localization system教程.pdfVIP

Spot: An accurate and efficient multi-entity device-free WLAN localization system Ibrahim Sabek Moustafa Youssef Comp. and Sys. Eng. Dept. Wireless Research Center Alexandria University, Egypt E-JUST, Egypt ibrahim.sabek@alexu.edu.eg moustafa.youssef@ejust.edu.eg 2 ABSTRACT 1 Device-free (DF) localization in WLANs has been introduced 0 2 as a value-added service that allows tracking indoor entities that do not carry any devices. Previous work in DF WLAN l u localization focused on the tracking of a single entity due to J the intractability of the multi-entity tracking problem whose 8 complexity grows exponentially with the number of humans 1 being tracked. ] In this paper, we introduce Spot as an accurate and ef- I ficient system for multi-entity DF detection and tracking. N Spot is based on a probabilistic energy minimization frame- . s work that combines a conditional random field with a Markov c model to capture the temporal and spatial relations between [ AccessPoint(AP) MonitoringPoint(MP) WirelessLink the entities’ poses. A novel cross-calibration technique is in- 1 troduced to reduce the calibration overhead of multiple en- v tities to linear, regardless of the number of humans being Figure 1: Typical architecture of a DF WLAN 5 tracked. This also helps in increasing the system accuracy. localization system. 6