Positioning system and method with multipath mitigation
AssigneeSemtech Corporation
InventorMengkang Peng
Life of this patent
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Abstract
The present invention proposed a weighted Centroid Localisation (WCL) algorithm, which does the location estimation based on the known positions of the gateways and the measurements times of arrival (TOA) at the gateways. The algorithm computes the weight of the gateway based on their rank when the gateways are sorted by their TOA. Simulations have demonstrated the algorithm's robustness under different multipath/fading channel conditions and its good location performance.
Claims16
A system comprising at least a mobile device and a plurality of gateways whose positions are known, wherein the gateways are operatively arranged receive a radio signal from the mobile device and to determine a time of arrival of said signal at the gateway, the system comprising a solver unit operatively arranged to compute the position of the mobile device based on said times of arrival, characterised in that the solver unit is arranged to assign to each gateway a weight factor dependent from its rank when the gateways are sorted by their received time of arrival, whereby those gateways whose time of arrival is earlier are assigned a heavier weight factor, the system being further arranged to compute the position of the mobile device by a weighted sum of the position of the gateways using said weight factors.
A method of determining the position of a mobile device relative to a plurality of gateways whose positions are known, comprising:
- determining for each gateway a time of arrival of the signal,
- assigning to each gateway a weight factor dependent from the rank it occupies when the gateways are sorted by their time of arrival, whereby those gateways whose time of arrival is earlier are assigned a heavier weight factor,
- computing the position of the mobile device by a weighted sum of the position of the gateways using said weight factors.
Dependencies are inferred from the claim text.