US 2003/0146871 A1 · Wireless location using signal direction and time difference of arrival

Abstract

A location system is disclosed for commercial wireless telecommunication infrastructures. The system is an end-to-end solution having one or more location centers for outputting requested locations of commercially available handsets or mobile stations (MS) based on, e.g., CDMA, AMPS, NAMPS or TDMA communication standards, for processing both local MS location requests and more global MS location requests via, e.g., Internet communication between a distributed network of location centers. The system uses a plurality of MS locating technologies including those based on: (1) two-way TOA and TDOA; (2) pattern recognition; (3) distributed antenna provisioning; and (4) supplemental information from various types of very low cost non-infrastructure base stations for communicating via a typical commercial wireless base station infrastructure or a public telephone switching network. Accordingly, the traditional MS location difficulties, such as multipath, poor location accuracy and poor coverage are alleviated via such technologies in combination with strategies for (a) automatically adapting and calibrating system performance according to environmental and geographical changes; (b) automatically capturing location signal data for continual enhancement of a self-maintaining historical data base retaining predictive location signal data; (c) evaluating MS locations according to both heuristics and constraints related to, e.g., terrain, MS velocity and MS path extrapolation from tracking and (d) adjusting likely MS locations adaptively and statistically so that the system becomes progressively more comprehensive and accurate. Further, the system can be modularly configured for use in location signaling environments ranging from urban, dense urban, suburban, rural, mountain to low traffic or isolated roadways. Accordingly, the system is useful for 911 emergency calls, tracking, routing, people and animal location including applications for confinement to and exclusion from certain areas.

Claims47

Dependent claims

A method for locating a wireless mobile station using wireless signal measurements obtained from transmissions between said mobile station and a plurality of base stations capable of wirelessly detecting said mobile station, comprising:

providing first and second mobile station location estimators, wherein said location estimators provide location estimates of said mobile station when said location estimators receive wireless signal measurements obtained from transmissions between said mobile station and the base stations, wherein:
(A) said first location estimator is capable of performing one or more of the techniques:
(a) a triangulation technique to determine, for each of three or more of the base stations, a distance between the mobile station and the base station using the wireless signal measurements;
(b) a learning technique, wherein said learning technique determines an association for associating:
the wireless signal measurements, and data indicative of a location for the mobile station, wherein said association is determined by a training process using a plurality of data pairs, each said pair including:
first information indicative of a location of some mobile station, and second information from wireless signal measurements between said some mobile station and one or more of the base stations when said some mobile station is at the location;
(c) a stochastic technique, wherein each said stochastic technique uses a statistical correlation for correlating:
the wireless signal measurements, and data indicative of a location for the mobile station, wherein said correlation is used for determining a probability that the mobile station is within an area, and
(B) for at least a particular one of said techniques performed by said first location estimator, said second location estimator does not perform said particular technique;
first supplying said first location estimator with first data from the wireless signal measurements;
first generating, by said first location estimator, first location related information having at least a first estimate of the mobile station's location;
second supplying said second location estimator with second data from the wireless signal measurements;
second generating, by said second location estimator, second location related information having at least a second estimate of the mobile station's location;
determining a resulting location estimate of the mobile station using:
(a) a first value obtained from said first location related information, and (b) a second value obtained from said second location related information.

12 more elements

A location system for locating a mobile station, wherein said mobile station is one of a plurality of mobile stations, and wireless signal measurements are capable of being obtained from wireless transmissions between the plurality of mobile stations and a plurality of base stations, the improvement characterized by:

one or more location estimators, each said location estimator for estimating a location for each of one or more individual mobile stations of the plurality of mobile stations, when said location estimator is supplied with data from a set of said wireless signal measurements obtained from wireless transmissions between the individual mobile station and said plurality of base stations;
an archive for storing a plurality of data item collections, wherein for each geographical location of a plurality geographical locations, there is one of said data item collections having (a1) and (a2):
(a1) a representation of the geographical location, and
(a2) a set of said] wireless signal measurements corresponding to one of the plurality of mobile stations transmitting from approximately the geographical location of (a1);
a performance estimator for determining, for each one of said location estimators, corresponding one or more performance measurements indicative of a previous performance of said one location estimator in locating one or more of the plurality of mobile stations, wherein said corresponding performance measurements are determined using location estimates generated by said one location estimator when said set of (a2), for some of said data item collections, is supplied to said one location estimator;
a controller for activating a group of at least one of said location estimators for generating corresponding location estimates of said mobile station when a first said set of wireless signal measurements is obtained from wireless transmissions between said mobile station and said plurality of base stations, wherein one or more location hypotheses are generated, each said location hypothesis having:
(b1) an hypothesized location estimate of said mobile station obtained using the corresponding location estimate generated by a location estimator of said group,
(b2) a likelihood value indicating a likelihood of said mobile station being at a location represented by said hypothesized location estimate of (b1), wherein said corresponding performance measurements for said location estimator providing the location estimate of (b1) are used in determining said likelihood value;
a location estimator for determining a resulting location estimate of said mobile station, said resulting location estimate being derived using said hypothesized location estimates and said likelihood values from said one or more location hypotheses.

6 more elements

A method for locating a mobile station, wherein said mobile station is one of a plurality of mobile stations, and wireless signal measurements are capable of being obtained from wireless transmissions between the plurality mobile stations and a network of base stations, wherein said base stations in the network are cooperatively linked for providing wireless communication with each of the mobile stations, the improvement characterized by:

providing a mobile station location estimator for estimating locations of one or more individual mobile stations of said plurality of mobile stations when said location estimator is supplied with said wireless signal measurements obtained from wireless transmissions between the individual mobile station and said network of base stations;
storing a plurality of data item collections, wherein for each of a plurality of geographical locations, there is one of said data item collections having:
(a1) a representation of the geographical location, and
(a2) a representation of said wireless signal measurements between one of the mobile stations and the base stations when said one mobile station is approximately at the geographical location of (a1);
generating, from said wireless signal measurements between said mobile and said base stations, an initial location estimate of said mobile;
obtaining a first set of one or more additional location estimates generated by said location estimator, wherein each said additional location estimate is generated from said representations of wireless signal measurements of (a2) for one of said data item collections, and wherein at least a majority of said additional location estimates are within a predetermined distance of said initial location estimate;
deriving an adjusted location estimate from said initial location estimate using a second set of said geographical location representations of (a1) for said data item collections whose representations of wireless signal measurements of (a2) were used to generate one of said additional location estimates of said set.

4 more elements

A location system for locating mobile stations from received wireless signal measurements obtained from transmissions between said mobile stations and a network of base stations, wherein said base stations in the network are cooperatively linked for providing wireless communication, the improvement characterized by:

one or more location estimators for estimating locations of said mobile stations, such that for each of said mobile stations, when said location estimators are supplied with measurements of wireless signals obtained from transmissions between:
the mobile station, at a corresponding geographical location from which the mobile station is transmitting, and said network of base stations, at least one location estimate is generated;
a location estimate adjuster for deriving a first adjusted location estimate from a first location estimate generated by a first of said location estimators supplied with said wireless signal measurements obtained from transmissions between:
(i) a particular one of said mobile stations, at a particular location, and (ii) said base stations, wherein:
(a1) said first adjusted location estimate has a corresponding confidence value indicative of a likelihood of the particular geographical location being a location represented by the first adjusted location estimate,
(a2) said first adjusted location estimate is determined using additional location estimates generated:
(i) previously to the generation of said first initial location estimate, and (ii) by said first location estimator;
a most likely estimator for determining a most likely location estimate of the particular geographical location of the particular mobile station, said most likely location estimate being derived using said first adjusted location estimate and its corresponding confidence value.

5 more elements

A location system for locating mobile stations from received wireless signal measurements obtained from transmissions between said mobile stations and a network of fixed location transceivers, wherein said transceivers in the network are cooperatively linked for providing wireless communication with said mobile stations, the improvement characterized by:

an archive for storing a plurality of data item collections, wherein for each location of a plurality geographical locations, there is one of said data item collections having (a1) and (a2):
(a1) a representation of the geographical location,
(a2) a set of said wireless signal measurements obtained from transmissions between one of said mobile stations and said fixed location transceivers, wherein the one mobile station transmits from approximately the geographical location;
a plurality of trainable location estimators, each said trainable location estimator for generating a geographical location estimates for said mobile stations, wherein for each said trainable location estimator:
(b1) there is a corresponding group of wireless signal measurement parameters, wherein for said trainable location estimator to generate a location estimate of an individual one of said mobile stations, at least some of said parameters must be instantiated with values obtained from transmissions between said individual mobile station and said fixed location transceivers,
(b2) there is a different corresponding group of wireless signal measurement parameters for another of said trainable location estimators, and
(b3) said trainable location estimator learns by associating, for each of at least some of said data item collections, said geographical location representation (a1) of the data item collection with said set of said wireless signal measurements (a2) of the data item collection;
a location estimator selector for selecting one or more of said plurality of trainable location estimators for generating mobile station location estimates, wherein when each of said selected location estimators has its corresponding group of wireless signal measurement parameters instantiated with values obtained from transmissions between one of said mobile stations and said fixed location transceivers, said selected location estimator generates a location estimate of the one mobile station;
wherein for locating a particular one of said mobile stations, said location estimator selector selects a particular set of said trainable location estimators whose corresponding group of wireless signal measurement parameters can have at least some said parameters instantiated using wireless signal measurements obtained from transmissions between said particular mobile station and said fixed location transceivers;
a location estimator for determining a resulting location estimate of said particular mobile station, said location estimator receiving location estimates from trainable location estimators of said particular set.

7 more elements

A location system for receiving wireless signal measurements of wireless signals transmitted between a plurality mobile stations and a network of base stations, wherein said base stations in the network are cooperatively linked for providing wireless communication, the improvement characterized by:

a plurality of mobile station location estimators for estimating locations of said mobile stations, such that when said location estimators are supplied with said measurements of wireless signals transmitted between one of the mobile stations and said network of base stations, said location estimators output corresponding initial location estimates of a geographical location of said one mobile station, wherein at least two of said mobile station location estimators of said plurality of mobile station location estimators include a different one of the following (a) through (f):
(a) a pattern recognition component for estimating a location of said one mobile station from a pattern in the wireless signal measurements of transmissions between the network and said one mobile station;
(b) a trainable mobile station location estimating component for estimating a location of said one mobile station, wherein said trainable mobile station location estimating component is capable of being trained to associate:
(i) each location of a plurality of geographical locations with (ii) corresponding measurements of wireless signals transmitted between a specified one of said mobile stations and the network, wherein said specified mobile station is approximately at the location;
(c) a triangulation component for estimating a location of said one mobile station, wherein said triangulation component utilizes said measurements of wireless signals between said one mobile station and three of the base stations for triangulating a location estimate of said one mobile station;
(d) a statistical component utilizing a statistical regression technique for estimating a location of said one mobile station;
(e) a mobile base station component for estimating a location of said one mobile station, wherein said mobile base station component utilizes location information received from a mobile base station that detects said one mobile station;
(f) a negative logic component for estimating an area of where said one mobile station is unlikely to be located;
and
a most likely estimator for determining a most likely location estimate of said one mobile station, said most likely location estimate being a function of said plurality of location estimates.

7 more elements

A method for locating a particular wireless mobile station using measurements of particular wireless signals, wherein at least one of:

said measurements and said particular wireless signals are transmitted between said wireless mobile station and at least one of a plurality of transceivers, wherein said transceivers are capable of at least wireless detection of a plurality of wireless transmitting mobile stations including said particular mobile station, comprising:
providing a first and second mobile station location estimators, wherein each of said location estimators is capable of providing a location estimate for each mobile station of at least some of said mobile stations when said location estimator is supplied with corresponding data obtained from received wireless signal measurements communicated between the mobile station and one or more of said plurality of transceivers, wherein:
said first location estimator performs one or more triangulation techniques, wherein each said triangulation technique determines for each of one or more of said mobile stations, and for each transceiver of a set of three or more of said transceivers, a distance between the mobile station, and said transceiver, each said distance determined from data resulting from received measurements of wireless signals communicated between the mobile station and said transceiver, and said second location estimator does not perform any said triangulation technique;
first supplying said first location estimator with first corresponding data obtained from received wireless signal measurements communicated between said particular mobile station and one or more of said plurality of transceivers;
second supplying said second location estimator with second corresponding data obtained from received wireless signal measurements communicated between said particular mobile station and one or more of said plurality of transceivers;
first generating, by said first location estimator, first location related information having at least a first estimate for the mobile station's location;
second generating, by said second location estimator, second location related information having at least a second estimate for the mobile station's location;
determining a resulting location estimate of the mobile station using:
(a) a first value obtained from said first location related information, and (b) a second value obtained from said second location related information.

6 more elements

A method for locating a particular wireless mobile station using measurements of particular wireless signals, wherein at least one of:

said measurements and said particular wireless signals are transmitted between said wireless mobile station and at least one of a plurality of transceivers, wherein said transceivers are capable of at least wireless detection of a plurality of wireless transmitting mobile stations including said particular mobile station, comprising:
providing a first and second mobile station location estimators, wherein each of said location estimators is capable of providing a location estimate for each mobile station of at least some of said mobile stations when said location estimator is supplied with corresponding data obtained from received wireless signal measurements communicated between the mobile station and one or more of said plurality of transceivers, wherein:
said first location estimator performs one or more global positioning techniques, wherein each said global positioning technique determines for each of one or more of said mobile stations, corresponding data resulting from received measurements of wireless signals from one or more global positioning satellites, said corresponding data for determining a location of the mobile station, and said second location estimator does not perform any said global positioning technique;
first supplying said first location estimator with first corresponding data obtained from wireless signal measurements communicated between said particular mobile station and one or more of said plurality of transceivers;
second supplying said second location estimator with second corresponding data obtained from wireless signal measurements communicated between said particular mobile station and one or more of said plurality of transceivers;
first generating, by said first location estimator, first location related information having at least a first estimate for said particular mobile station's location;
second generating, by said second location estimator, second location related information having at least a second estimate for said particular mobile station's location;
determining a resulting location estimate of said particular mobile station using:
(a) a first value obtained from said first location related information, and (b) a second value obtained from said second location related information.

6 more elements

A method for locating a particular wireless mobile station using measurements of particular wireless signals, wherein at least one of:

said measurements and said particular wireless signals are transmitted between said wireless mobile station and at least one of a plurality of transceivers, wherein said transceivers are capable of at least wireless detection of a plurality of wireless transmitting mobile stations including said particular mobile station, comprising:
providing a first and second mobile station location estimators, wherein each of said location estimators is capable of providing a location estimate for each mobile station of at least some of said mobile stations when said location estimator is supplied with corresponding data obtained from received wireless signal measurements communicated between the mobile station and one or more of said plurality of transceivers, wherein:
said first location estimator performs one or more coverage area analysis techniques, wherein each said coverage area analysis technique determines for each of one or more of said mobile stations, an area:
(i) included in a corresponding coverage area for each of one or more of said transceivers that detect the mobile station, and (ii) excluded from a corresponding coverage area for each of one or more of said transceivers that can not detect the mobile station, and said second location estimator does not perform any said coverage area analysis technique;
first supplying said first location estimator with first corresponding data obtained from wireless signal measurements communicated between said particular mobile station and one or more of said plurality of transceivers;
second supplying said second location estimator with second corresponding data obtained from wireless signal measurements communicated between said particular mobile station and one or more of said plurality of transceivers;
generating, by said first and a second of said location estimators, respectively, first and second different initial location estimates of said particular mobile station;
determining a location estimate of said particular mobile station as a function of at least one of:
(a) said first and second initial location estimates, and (b) a rating of said first and second initial location estimates.

6 more elements

A method for locating a wireless mobile station capable of wireless communication with a plurality of base stations, comprising:

providing a plurality of mobile station location estimators, wherein said location estimators provide different location estimates of said mobile station when said location estimators are supplied with location information derived from signal measurements that are transmitted between said mobile station and said plurality of base stations;
receiving measurements of wireless signals transmitted:
(a) from one or more global positioning satellites, and (b) between said wireless mobile station and said plurality of base stations;
first generating, by a first of said location estimators, a first time series of one or more location estimates of said mobile station when at least a portion of said measurements are obtained for global positioning satellite signals;
second generating, by a second of said location estimators, a second time series of one or more location estimates of said mobile station when at least a portion of said measurements provide measurements of wireless signals transmitted between said mobile station and at least one of base stations of said plurality of base stations;
determining a resulting time series of one or more resulting location estimates of said mobile station, wherein for each time of said resulting time series when one of said resulting location estimates is derived, said derivation uses at least one location estimate:
(a) that is most recently generated by said first location estimator, and (b) that is most recently generated by said second location estimator.

4 more elements

Dependencies are inferred from the claim text.

Wireless location using signal direction and time difference of arrival

Life of this patent

Wireless location using signal direction and time difference of arrival

Life of this patent

Abstract

Claims47