User Localization in UMTS by Spectrum Estimation Method

Abstract

Geo-location techniques have recently become more important since Location Aware Wireless Systems are spreading all over the world and Location Based Services have now become a kind of necessity for users. TOA and TDOA are the most useful methods of geo-locating but the resolution of location estimation is dependent on the accuracy of TOA/TDOA estimation of received signals. The accuracy of TOA/TDOA estimation in usual methods such as correlation in different types of propagation environment is not precise enough especially when there is no line of sight signal between transmitter and receiver or the LOS signal is not the strongest received signal compared with the others. Therefore, in these cases it is necessary to find and apply methods to distinguish the LOS signal from other signals and extract the TOA of LOS signal so that reasonable resolution for the estimation process can be achieved. In this paper one of the spectrum estimation methods called MUSIC is applied in time domain and its efficiency and ability in extracting TOA for received signals will be shown.