Assessment of Cramer-Rao lower bounds of WLAN user location estimation

The location estimation techniques based on wireless local area network (WLAN) have received increasing attention in recent years. To obtain location information, localization methods employing received signal strength (RSS) are widely used. This paper describes Cramer-Rao lower bounds (CRLB) of WLAN user location estimation in an auditorium. The physical layout of the auditorium is substantially different when comapared to the usual halls. The CRLBs are computed using real time radio signal strength measurements performed by user´s mobile terminal. The distance error lower bound provides the reference for the accuracy of node localization. The numerical results shows that the mean location error is 1.95 m and is better as compared to the localization technique using linear least square estimate. The simulation results also demonstrate that the location accuracy improves for higher values of path loss exponent. Future directions of research are indicated.