Abstract:
A communications system, including at least one tag and a plurality of beacons. The tags are configured to detect beacon advertisement messages, initiate a connection with at least one of the plurality of and transmit a Constant Tone (CT) to the at least one of the plurality of beacons. The tag is further configured to determine a location thereof based on the sampled CT from both the beacon and the tag and then report the location via the one of the beacons and/or an access point. Phase ranging mitigation techniques which include hop duplication, hop interpolation and ADC DC offset correction are employed so as to provide more accurate ranging values even in the case where there are many other devices in local proximity and which are competing for use of the same RF channels as those used by the tags and beacons.
Abstract:
Systems and methods for providing improved accuracy for beacon-based location systems. A location estimation system may include a multi-beacon system which includes two or more beacons positioned proximate each other. The beacons emit correlated beacon frames which are time and data correlated. A mobile device receives the beacon signals and processes them to estimate the distance between the mobile device and the multi-beacon system. The mobile device processes the signals based on a correlation function of the beacons signal strength trends, which indicates homogeneity and reliability of the acquired signals. When the correlation is high, the two or more RSSI signals are stable and may be used for the distance estimation. When the correlation is low, at least one of the signals is irregular. The mobile device compensates for the irregular signal, thus improving distance estimation accuracy.
Abstract:
Die vorliegende Erfindung betrifft ein Verfahren und ein System zur Positionsbestimmung. Es ist Aufgabe der vorliegenden Erfindung, ein Verfahren und ein System zur eigenständigen, und in Bezug auf die Sender, kontaktlosen Positionsbestimmung eines Empfängers anzugeben, wobei eine exakte Positionsbestimmung unter Verwendung preiswerter Empfänger und möglichst weniger Sender gewährleistet sein soll, insbesondere in Bereichen, in denen GPS-Signale nicht verfügbar sind. Das erfindungsgemäße Verfahren weist folgende Verfahrensschritte auf: Aussenden elektromagnetischer Strahlung einer ersten Sendefrequenz (f 1 ) mittels des ersten Senders (1), wobei die erste Sendefrequenz (f 1 ) mit einer ersten Modulationsfrequenz (f M1 ) moduliert wird; Aussenden elektromagnetischer Strahlung einer zweiten Sendefrequenz (f 2 ) mittels des zweiten Senders (2), wobei die zweite Sendefrequenz (f 2 ) mit einer zweiten Modulationsfrequenz (f M2 ) moduliert wird, und wobei sich die erste Frequenz (f 1 ) von der zweiten Frequenz (f 2 ) derart unterscheidet, dass sich eine Schwebung mit einer Schwebungsfrequenz (f s ) ausbildet; Messen mindestens einer ersten Amplitude (A 1 ) der Schwebungsfrequenz (f s ) ab einem ersten Zeitpunkt (t 1 ) an einer ersten Position (x 1 ) des Empfängers (4); Messen mindestens einer zweiten Amplitude (A 2 ) der Schwebungsfrequenz (f s ) ab einem zweiten Zeitpunkt (t 2 ) an einer zweiten Position (x 2 ) des Empfängers (4); und Ermittlung der zweiten Position (x 2 ) des Empfängers (4) in Bezug zur ersten Position (x 1 ) des Empfängers (4) aus der mindestens einen ersten Amplitude (A 1 ) und der mindestens einen zweiten Amplitude (A 2 ) der Schwebungsfrequenz (f s ).
Abstract:
Determination of the location and bearing of an RF-tag is accomplished through extended radio frequency triangulation. A beacon arrangement determines the direction of an RF tag from a specially designed beacon node. RF-tag localization is achieved by performing this measurement from multiple spatially displaced beacon nodes. The beacon nodes are equipped with multiple antennas and transmit frames with each symbol cyclically switched to a different antenna. The symbols traveling different distances result in phase shifts within the frame received by the RF-tag. From the phase shifts and the known arrangements of the antennas the angle at which the RF-tag is RF visible from the specific beacon node can be estimated.
Abstract:
The present invention relates to a method or a system of using radio frequency signals to determine the position of an electronic apparatus (100, 200), such as a cellphone, within a communication network without affecting its ability to transmit audio and data information within a communication network. In particular, the present invention relates to a method or a system for position or distance (900) measurement using a radio frequency signal's phase change along its transmission pathway.