Analysis of a Device-Free Passive Tracking System in Typical Wireless Environments

Device-free passive (DfP) localization is a new concept in location determination where the tracked entity does not carry any device nor participate actively in the localization process. A DfP system operates by processing the received physical signal of a wireless transmitter at one or more monitoring points. The previously introduced DfP system was shown to enable the tracking of a single intruder with high accuracy in a highly controlled WLAN environment. In this paper, we propose and analyze different algorithms for DfP tracking in a typical indoor WLAN environment, rich in multipath. We also study the effect of the temporal and spatial changes in the environment on the accuracy of the system. In addition, we evaluate the effect of the different configurations of the wireless equipment placement on the DfP localization accuracy. Our results show that our proposed techniques can accurately track the user in typical environments, thus enabling a large number of DfP applications.