MOBILE POSITIONING TECHNIQUES

Abstract

Tracking and localization of mobile in telecomunication is becoming an important area for research, in emergency services. In cellular networks, mobile localization can provide various services like catching theifs ,locating stolen mobiles, for emergency calls, traffic control, and can predict the movement of users. Requirement of more accurate and reliable mobile positioning techniques is increasing day by day due to the evolution of location based sevices and applications. But the major challenge is to devlop a technology which can give sufficiently high accuracy even when the LOS path is blocked. So in practical cases the major source of problem is the absence of LOS path because NLOS path makes target to appear farther from its actual position, that is positive biasing and thereby increasing positioning error. This report discusses the complete analysis of range based methods of source localization ,then source location is estimated by time of arrival. To calculate estimated source location various non linear and linear approaches are used by minimizing the cost functions. MATLAB results show the variation in mean square position error with varying number of receivers, SNR etc. Then mobile estimation in mixed LOS/NLOS condition is considered.NLOS identification using Rician K-factor is evaluated and effect on RMSE due to number of NLOS BSs and radius of cell is studied.