US 2001/0022558 A1 · Wireless location using signal fingerprinting

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.

Claims124

Dependent claims

A method for locating wireless mobile stations using wireless signal measurements of wireless signals transmitted between said wireless mobile stations and a network of base stations, wherein said base stations in the network are cooperatively linked for providing wireless communications with said wireless mobile stations, comprising:

providing a plurality of mobile station location estimators, wherein said location estimators provide location estimates of said mobile stations when said location estimators are supplied with location information derived from wireless signal measurements of wireless signals transmitted between said mobile stations and the network of base stations;
generating, by a first and a second of said location estimators, respectively, first and second different initial location estimates of a particular one of said wireless mobile stations, using location information derived from wireless signal measurements of wireless signals transmitted between said particular mobile station and the network of base stations;
determining:
(a) first confidence data for a first location hypothesis of said particular mobile station, wherein:
(i) said first location hypothesis provides one of:
said first initial location estimate from said first location estimator, and a first successive location estimate of said particular mobile station, said first successive location estimate derived using said first initial location estimate, and
(ii) said first confidence data is indicative of a likelihood of said particular mobile station being at a location represented by said first location hypothesis;
and
(b) second confidence data for a second location hypothesis of said particular mobile station, wherein:
(i) said second location hypothesis provides one of:
said second initial location estimate from said second location estimator, and a second successive location estimate of said particular mobile station, said second successive location estimate derived using said second initial location estimate, and
(ii) said first confidence data is indicative of a likelihood of said particular mobile station being at a location represented by said first location hypothesis;
deriving a most likelihood location estimate of said particular mobile station, said most likely location estimate being dependent on each of:
said location estimates of said first and second location hypotheses, and, values of said first and second confidence data.

11 more elements

A location system for receiving 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 different 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;
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) a representation of the geographical location,
(a2) a set of said wireless signal measurements corresponding to one of said mobile stations transmitting from approximately the geographical location
(a3) for each location estimator of said plurality of location estimators, a corresponding initial location estimate generated when said set of said wireless signal measurements is supplied to said location estimator;
a means for constructing, for each of said location estimators, corresponding prediction measurements indicative of an historical accuracy of said location estimator, wherein for each said prediction measurement, there is:
(b1) a corresponding selected group of said data item collections used in determining said prediction measurement,
(b2) a collection of mappings, wherein each said mapping is an association between:
(i) one of said corresponding mobile station initial location estimates generated by said location estimator using said wireless measurements of one of said data item collections in said selected group, and (ii) the geographical location of the data item collection;
a means for determining, for an identified one of said mobile stations, a plurality of location hypotheses, wherein for each said location hypothesis:
(c1) said location hypothesis has a location estimate of said identified mobile station derived using at least one initial location estimate, wherein said initial location estimate is generated by one of said plurality of location estimators, said one location estimator being supplied with signal measurements of wireless signal transmissions between said identified mobile station and said network of base stations,
(c2) said location hypothesis has a confidence value used for indicating a likelihood of said identified mobile station being at a location represented by said location estimate for said location hypothesis, wherein one of said prediction measurements is used in determining said confidence value;
a most likely mobile station location estimator for determining a most likely location estimate of said identified mobile station, said most likely location estimate being derived using location estimates and confidence values from location hypotheses of said plurality of said location hypotheses.

10 more elements

A method for locating a mobile station by 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:

providing a mobile station location estimator for estimating locations of said mobile stations, such that when said location estimator is supplied with said measurements of wireless signals transmitted between one of the mobile stations and said network of base stations, said location estimator generates a initial location estimate of a geographical location of said one mobile station;
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 measurements of wireless signals transmitted between one of said mobile stations and the base stations when said one mobile station is approximately at the geographical location;
determining, from said initial location estimate, a corresponding adjusted location estimate as a function of historical initial location estimates generated by said mobile station location estimator when supplied with said signal measurements for representations of (a2) of said data item collections.

1 more element

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 one or more 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 one or more location estimators generate initial location estimates, wherein for a particular one of said mobile stations at a particular geographical location, at least first and second initial location estimates are generated;
a means for generating, for said first and second initial location estimates, first and second adjusted location estimates respectively, wherein:
(a1) said first adjusted location estimate has a corresponding confidence value indicative of a likelihood of the particular geographical location being at a location represented by the first adjusted location estimate,
(a2) said first adjusted location estimate is a function of other initial location estimates generated by said location estimator that generated said first initial location estimate,
(a3) said second adjusted location estimate has a corresponding confidence value indicative of a likelihood of the particular geographical location being at a location represented by the second adjusted location estimate, and
(a4) said second adjusted location estimate is a function of other initial location estimates generated by said location estimator that generated said second initial location estimate;
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 and second adjusted location estimates and their corresponding confidence values.

4 more elements

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 corresponding to one of said mobile stations transmitting from approximately the geographical location
a trainable location estimator for generating a geographical location estimate of one of said mobile stations when said trainable estimator is supplied with said measurements of wireless signals transmitted between one of said mobile stations and the network of base stations, wherein 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.

1 more element

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.

6 more elements

A method for locating a wireless mobile station, comprising:

determining one or more collections of one or more location hypotheses of a location of a particular mobile station, wherein, for each of said collections, said one or more location hypotheses of said collection are obtained using measurements of wireless signals transmitted between said particular mobile station and a network of base stations, wherein said wireless signals are transmitted during a time interval different from any other time interval for transmitting wireless signals whose measurements are used for obtaining said location hypotheses for a different one of said collections, and wherein each said location hypothesis of each said collection provides access to the following attributes:
(a) an estimate of the location of said particular mobile station,
(b) time related data for determining a measurement of time since the wireless signals, upon which said location estimate of the location hypothesis, were transmitted,
(c) a confidence providing a measurement of a likelihood that said particular mobile station is at a location represented by said location estimate attribute of said location hypothesis;
constructing one or more derived location hypotheses, wherein each said derived location hypothesis also has said attributes (a) through (c), and wherein at least one of said attributes, for each of said derived location hypotheses, is determined using said attributes of said location hypotheses of said collections;
estimating a location of said particular mobile station using said one or more derived location hypotheses.

3 more elements

A method for locating a wireless mobile station, comprising:

providing at least a first location estimator for estimating locations of a plurality of wireless mobile stations, wherein said first location estimator receives as input wireless signal measurements of wireless signals transmitted between said plurality mobile stations and a network of base stations, wherein for said network, said base stations in the network are cooperatively linked for providing wireless communication;
storing a plurality of data item collections, wherein for each of a plurality locations, there is one of said data item collections having:
(a) a representation of the location, and (b) said wireless signal measurements corresponding to one of said mobile stations transmitting from approximately the location;
activating said first location estimator with said wireless signal measurements of said data item collections for obtaining corresponding mobile station location estimates;
constructing a first set of said measurements for said first location estimator, wherein said first set includes values related to a predictiveness of a collection of mappings between:
(a) said corresponding mobile station location estimates, and (b) for each said corresponding mobile station location estimate, a corresponding verified mobile station location;
generating, by said first location estimator, a first initial location estimate from wireless signal measurements of wireless signals from transmissions between a first of said mobile stations and the base stations, wherein a location of said first mobile station is unknown;
obtaining an adjusted location estimate of said first mobile station, wherein said adjusted location estimate is obtained by using a subcollection of said mappings in a neighborhood of said first initial location estimate;
determining a confidence value related to a likelihood of said first mobile station being at a location represented by said adjusted location estimate, wherein said confidence is a function of at least one measurement in said first set of measurements.

6 more elements

A method for locating wireless mobile stations from measurements of wireless signals transmitted between the mobile stations and a network of base stations, wherein for said network, said base stations in the network are cooperatively linked for providing wireless communication, comprising:

storing a plurality of data item collections, wherein for each of a plurality locations, there is one of said data item collections having:
(a) a representation of the location, and (b) said wireless signal measurements corresponding to one of said mobile stations transmitting from approximately the location, wherein said wireless signal measurements are acceptable as input to a wireless mobile station location system;
determining a collection of parameters of said wireless mobile station location system that affect a performance of said wireless mobile station location system in locating mobile stations;
providing a population of representations for values of said collection of parameters to an adaptation component, wherein said adaptation component:
(a) generates, for said representations, configurations of said wireless mobile station location system, each said configuration corresponding to the values of one of said representations, and (b) determines, for each of at least some of said configurations, a location predicting performance using said plurality of data items for providing wireless signal measurements as input and said representations of locations for comparing with mobile station location outputs by the configuration;
determining a first of said configurations that an enhanced performance of said wireless mobile station location system;
using said first configuration for deriving a location estimate of a first one said mobile station, wherein said first configuration is provides with wireless signal measurements of wireless signals from transmissions between said first mobile station and the base stations, and wherein a location of said first mobile station is unknown.

4 more elements

Dependencies are inferred from the claim text.

Wireless location using signal fingerprinting

Life of this patent

Wireless location using signal fingerprinting

Life of this patent

Abstract

Claims124