A wireless approach to device-free localisation (DFL) for indoor environments

Determining the location of individuals within indoor locations can be useful in various scenarios including security, gaming and ambient assisted living for the elderly. Healthcare services globally are seeking to allow people to stay in their familiar home environments longer due to the multitude of benefits associated with living in non-clinical environments. Technology to determine an individual´s movements or lack of movement is key to ensuring that home emergencies are detected and responded to promptly. This paper proposes a device-free wireless-based localisation (DFL) system which would enable the individual to proceed with normal daily activities without the constraint of having to wear a traceable device. The principal behind this is that the human body absorbs/reflects the radio signal being transmitted from a transmitter to one or more receiving stations. The system design procedure facilitates the use of a minimum number of wireless nodes with the aid of a principle component analysis (PCA) based intelligent signal processing technique. Results demonstrate that human detection and tracking are possible to within 1m resolutions with a minimal wireless hardware infrastructure.