Patent ID: 7783301
Filing Date: 2010-08-24
Classification: G01S

Abstract:
1. A method to determine a location of a communications device, comprising: measuring a time of arrival for each pulse received at a receiver; generating a plurality of transmission path-time matching hypotheses, each transmission path-time matching hypothesis including a set of hypothetical matches between each received pulse and a possible transmission path between a transmitter and the receiver, wherein each hypothetical match corresponds to the received pulse being able to have traveled over the possible transmission path between the transmitter and the receiver based on a transmit time of the received pulse, wherein generating the plurality of transmission path-time matching hypotheses comprises: determining an intersection error for each transmission path-time matching hypothesis, wherein each hypothetical match defines a locus of possible communications device locations and an intersection of loci of the set of different hypothetical matches for each transmission path-time matching hypothesis provides an estimate of the location of the communications device for that transmission path-time matching hypothesis, the intersection error for each transmission path-time matching hypothesis providing an indication that the intersection of loci for each transmission path-time matching hypothesis being substantially at a single point to estimate the location of the communications device; and estimating the location of the communications device as the intersection of loci for the transmission path-time matching hypothesis with a lowest intersection error.