|Start:||01 January 2007|
|End:||31 January 2009|
|Department:||Statistical Inference (SI)|
|Code:||Project contract/code: 2006-27641-E|
Positioning systems are based on time delay and frequency-shift estimation of the incoming signals in the receiver side. Sources of accuracy degradation in satellite-based navigation systems are well-known, and their mitigation has deserved the attention of a number of researchers in latter times. While atmospheric-dependant sources (delays that depend on the ionosphere and troposphere conditions) can be greatly mitigated by differential systems external to the receiver’s operation, the multipath effect is location-dependant and remains as the most important cause of accuracy degradation in time delay estimation, and consequently in position estimation, becoming a signal processing challenge. For example, a specific problem in mountain regions, with deep valleys, is the shadowing effect. As a result of that, large areas of the territory are not well covered by satellite signals. The mitigation of multipath effects described in the previous lines is often not sufficient to ensure the positioning service continuity. In this respect, the project aims at establishing a co-operation (hybridation) between the localization capabilities of existing telecommunications networks (GSM, GPRS, UMTS, WiFi, …) and the satellite-based (GNSS, Galileo, …) systems.