Indoor positioning has become an important research field in recent years. This is due to the potential services or products that can be offered, which would be very useful for users in several applications, and the interesting commercialization possibilities. But nowadays the most developed positioning systems are used outdoors, and for example GNSSs do not provide indoor coverage, so the efforts are focused on other local radio technologies. In particular, ultra-wideband is the object of this thesis.
In this thesis a set of cooperative algorithms are presented and intended for use in the localization phase of an ultra-wideband positioning system. Different approaches and points of view are shown in the literature related to the localization problem. Here there is a revision of the main concepts as well as some software implementations and their results in MATLAB, always trying to evaluate which is the best option in each situation.
The Ultra-Wideband system considered in this thesis consists of a set of nodes, some of which have unknown positions that have to be estimated by the algorithms. These nodes have the ability of calculating distances between each other by measuring the round-triptime of ultra-wideband pulse signals. The distances are used as inputs to the algorithms to calculate the estimated positions of the nodes as outputs. The most remarkable detail is the cooperation, which means that the distances between any pair of nodes is used even when both have unknown positions, taking advantage of that information.
The results show that using the cooperation, the algorithms can be very precise even in very demanding conditions when nodes can not communicate with the whole network due to a range limitation of the technology or physical obstacles. Therefore, cooperative algorithms represent a way to further investigate and improve the solutions for indoor positioning.
2012. , 74 p.