Exploiting RF signal attenuation for passive indoor location tracking of an object

This paper presents a conceptual design for tracking the location of a moving object within an indoor array of wireless transceivers passively, without the need for an electronic device or tag attached to the object. The conventional problem of signal attenuation due to object blocking, or shadowing prevalent in a typical wireless communication system is exploited to track an object. This is based on the principle of signal attenuation resulting from the object blocking the line-of-sight (LOS) link in a transceiver set. In particular, Wi-Fi transceivers operating at a frequency of 2.4 GHz (IEEE 802.11g standard) have been investigated. The estimated location is approximated using the measured received signal strength (RSS) and the relative distances between the transmitters and a receiver. Experimental results within a 3 m × 5 m area show that it is possible to track a human being using the proposed configuration.