Positioning with 3GPP-LTE based Cellular Wireless Communication Systems: Interference, Multipath and Non-Line-of-Sight

Kurzfassung

Positioning services and applications for mobile phones have become very important in recent years and will pay a fundamental role in future wireless communication systems. Presently, to get accurate position information of current mobile phones global navigation satellite systems are used. Unfortunately these systems do not provide good coverage in urban or indoor scenarios. In contrast, cellular wireless communication systems are designed to provide excellent coverage in these scenarios. Hence this thesis studies the positioning of mobile phones in a 3GPP-LTE based cellular wireless communication system with respect to adverse propagation conditions as interference, multipath and Non-Line-of-Sight (NLOS). Therefore a cellular network simulator based on the 3GPP-LTE standard and the WINNER II channel model is developed to study the influences of these adverse effects on single link time measurements. Furthermore a Time-Difference-of-Arrival (TDOA) positioning receiver based on a Gauss-Newton algorithm for the positioning approach is developed. In addition signal processing algorithms for the mitigation of the adverse propagation effects are implemented to evaluate the associated improvements for the positioning. Therefore algorithms for interference cancellation, multipath and NLOS mitigation are developed and implemented in the receiver. To study the effect of these algorithms, different combinations of these techniques are evaluated in simulations. Furthermore the influence of different receiver bandwidths on the positioning accuracy in the developed simulation environment is determined.