Wireless location (localisation) refers to estimating the physical coordinates of a mobile user in
cellular or wireless local area network (WLAN) environments. Location information are increasingly
being used in a wide variety of wireless applications, and it is estimated that this fast growing
segment of the wireless market will generate annual revenues of the order of US$15 billion
worldwide. Examples of location based applications include asset tracking, fleet management and
location sensitive billing.
Techniques for wireless localization using radio signals usually involve estimating either the Angle
of Arrival (AOA), Time of Arrival (TOA), signal strength (SS) or a combination of these quantities.
The main sources of error for these methods include multipath effects, multiple access interference and
non-line of sight (NLOS) propagation. Among these errors, the non-line of sight error is probably
the most crucial one.
