WO2010080675A2 - Procédé et système de sélection de satellites optimaux pour une localisation par a-gps de combinés dans des réseaux sans fil - Google Patents

Procédé et système de sélection de satellites optimaux pour une localisation par a-gps de combinés dans des réseaux sans fil Download PDF

Info

Publication number
WO2010080675A2
WO2010080675A2 PCT/US2009/069709 US2009069709W WO2010080675A2 WO 2010080675 A2 WO2010080675 A2 WO 2010080675A2 US 2009069709 W US2009069709 W US 2009069709W WO 2010080675 A2 WO2010080675 A2 WO 2010080675A2
Authority
WO
WIPO (PCT)
Prior art keywords
satellites
determining
boundary
sets
function
Prior art date
Application number
PCT/US2009/069709
Other languages
English (en)
Other versions
WO2010080675A3 (fr
Inventor
Peter John Rhodes
Neil Harper
Original Assignee
Andrew Llc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US12/392,400 external-priority patent/US9250330B2/en
Priority claimed from US12/395,803 external-priority patent/US7928903B2/en
Application filed by Andrew Llc filed Critical Andrew Llc
Publication of WO2010080675A2 publication Critical patent/WO2010080675A2/fr
Publication of WO2010080675A3 publication Critical patent/WO2010080675A3/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/13—Receivers
    • G01S19/24—Acquisition or tracking or demodulation of signals transmitted by the system
    • G01S19/25—Acquisition or tracking or demodulation of signals transmitted by the system involving aiding data received from a cooperating element, e.g. assisted GPS
    • G01S19/258—Acquisition or tracking or demodulation of signals transmitted by the system involving aiding data received from a cooperating element, e.g. assisted GPS relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/13—Receivers
    • G01S19/24—Acquisition or tracking or demodulation of signals transmitted by the system
    • G01S19/28—Satellite selection

Definitions

  • Radio communication systems generally provide two-way voice and data communication between remote locations. Examples of such systems are cellular and personal communication system (“PCS”) radio systems, trunked radio systems, dispatch radio networks, and global mobile personal communication systems (“GMPCS”) such as satellite-based systems. Communication in these systems is conducted according to a pre-defined standard. Mobile devices or stations, also known as handsets, portables or radiotelephones, conform to the system standard to communicate with one or more fixed base stations. It is important to determine the location of such a device capable of radio communication especially in an emergency situation. In addition, in 2001 the United States Federal Communications Commission (“FCC”) required that cellular handsets must be geographically locatable. This capability is desirable for emergency systems such as Enhanced 911 (“E-911"). The FCC requires stringent accuracy and availability performance objectives and demands that cellular handsets be locatable within 100 meters 67% of the time for network based solutions and within 50 meters 67% of the time for handset based solutions.
  • PCS personal communication system
  • GPCS global mobile personal communication systems
  • E-911 Enhanced
  • GNSS Global Navigation Satellite System
  • GPS Global Positioning System
  • FIG. 1 is a schematic representation of a constellation 100 of GPS satellites 101.
  • GPS may include a constellation of GPS satellites 101 in non-geosynchronous orbits around the earth.
  • the GPS satellites 101 travel in six orbital planes 102 with four of the GPS satellites 101 in each plane.
  • Each orbital plane has an inclination of 55 degrees relative to the equator.
  • each orbital plane has an altitude of approximately 20,200 km (10,900 miles).
  • the time required to travel the entire orbit is just under 12 hours. Thus, at any given location on the surface of the earth with clear view of the sky, at least five GPS satellites are generally visible at any given time.
  • GPS position determination is made based on the time of arrival ("TOA") of various satellite signals.
  • TOA time of arrival
  • Each of the orbiting GPS satellites 101 broadcasts spread spectrum microwave signals encoded with satellite ephemeris information and other information that allows a position to be calculated by the receiver.
  • GPS measurements corresponding to each correlator channel with a locked GPS satellite signal are available for GPS receivers.
  • the two carrier signals, Ll and L2 possess frequencies of 1.5754 GHz and 1.2276 GHz, or wavelengths of 0.1903 m and 0.2442 m, respectively.
  • the Ll frequency carries the navigation data as well as the standard positioning code, while the L2 frequency carries the P code and is used for precision positioning code for military applications.
  • the signals are modulated using bi-phase shift keying techniques.
  • the signals are broadcast at precisely known times and at precisely known intervals and each signal is encoded with its precise transmission time.
  • the L2C signal is a second civilian frequency transmitted by GPS satellites.
  • Ll transmits the Coarse Acquisition ("C/ A") code.
  • L2C transmits L2CM (civil-moderate) and L2CL (civil long) codes. These codes allow a device to differentiate between satellites that are all transmitting on the same frequency.
  • the C/A code is 1 milliseconds long, the L2CM is 20 milliseconds long and the L2CL is 1.5 seconds long.
  • the L2C codes provide a more robust cross-correlation performance so that reception of weak GPS signals is less affected by simultaneously received strong GPS signals.
  • the civil navigation message (“CNAV”) is the broadcast model that can be transmitted on the L2C and provides a more accurate and frequent message than the legacy navigation message (“NAV").
  • GPS receivers measure and analyze signals from the satellites, and estimate the corresponding coordinates of the receiver position, as well as the instantaneous receiver clock bias. GPS receivers may also measure the velocity of the receiver. The quality of these estimates depends upon the number and the geometry of satellites in view, measurement error and residual biases. Residual biases generally include satellite ephemeris bias, satellite and receiver clock errors, and ionospheric and tropospheric delays. If receiver clocks were perfectly synchronized with the satellite clocks, only three range measurements would be needed to allow a user to compute a three- dimensional position. This process is known as multilateration.
  • This clock bias is determined by computing a measurement from a fourth satellite using a processor in the receiver that correlates the ranges measured from each satellite. This process requires four or more satellites from which four or more measurements can be obtained to estimate four unknowns x, y, z, b.
  • the unknowns are latitude, longitude, altitude and receiver clock offset.
  • the amount b, by which the processor has added or subtracted time, is the instantaneous bias between the receiver clock and the satellite clock. It is possible to calculate a location with only three satellites when additional information is available.
  • an arbitrary satellite measurement may be included that is centered at the center of the earth and possesses a range defined as the distance from the center of the earth to the known altitude of the handset or mobile device.
  • the altitude of the handset may be known from another sensor or from information from the cell location in the case where the handset is in a cellular network.
  • satellite coordinates and velocity have been computed inside the GPS receiver.
  • the receiver obtains satellite ephemeris and clock correction data by demodulating the satellite broadcast message stream.
  • the satellite transmission contains more than 400 bits of data transmitted at 50 bits per second.
  • the constants contained in the ephemeris data coincide with Kepler orbit constants requiring many mathematical operations to turn the data into position and velocity data for each satellite.
  • this conversion requires 90 multiplies, 58 adds and 21 transcendental function cells (sin, cos, tan) in order to translate the ephemeris into a satellite position and velocity vector at a single point, for one satellite.
  • Most of the computations require double precision, floating point processing.
  • the mobile device must include a high-level processor capable of the necessary calculations, and such processors are relatively expensive and consume large amounts of power.
  • Portable devices for consumer use e.g., a cellular phone or comparable device, are preferably inexpensive and operate at very low power. These design goals are inconsistent with the high computational load required for GPS processing.
  • the slow data rate from the GPS satellites is a limitation. GPS acquisition at a GPS receiver may take many seconds or several minutes, during which time the receiver circuit and processor of the mobile device must be continuously energized.
  • circuits are de-energized as much as possible.
  • the long GPS acquisition time can rapidly deplete the battery of a mobile device. In any situation and particularly in emergency situations, the long GPS acquisition time is inconvenient.
  • A-GPS Assisted-GPS
  • TTFF time to first fix
  • a communications network and associated infrastructure may be utilized to assist the mobile GPS receiver, either as a standalone device or integrated with a mobile station or device.
  • the general concept of A-GPS is to establish a GPS reference network (and/or a wide-area D-GPS network or a wide area reference network (“WARN”)) including receivers with clear views of the sky that may operate continuously.
  • This reference network may also be connected with the cellular infrastructure, may continuously monitor the real-time constellation status, and may provide data for each satellite at a particular epoch time.
  • the reference network may provide ephemeris information, UTC model information, ionosphere model information, and other broadcast information to the cellular infrastructure.
  • the GPS reference receiver and its server may be located at any surveyed location with an open view of the sky.
  • Typical A-GPS information may include data for determining a GPS receiver's approximate position, time synchronization mark, satellite ephemerides, various model information and satellite dopplers. Different A-GPS services may omit some of these parameters; however, another component of the supplied information is the identification of the satellites for which a device or GPS receiver should search.
  • a mobile device From such assistance data, a mobile device will attempt to search for and acquire satellite signals for the satellites included in the assistance data. If, however, satellites are included in the assistance data that are not measurable by the mobile device (e.g., the satellite is no longer visible, etc.), then the mobile device will waste time and considerable power attempting to acquire measurements for the satellite.
  • A-GPS handset implementations generally rely upon provided assistance data to indicate which satellites are visible. As a function of the assistance data, a mobile device will attempt to search for and acquire satellite signals for the satellites included in the assistance data. A-GPS positioning may also rely upon the availability of a coarse location estimate to seed the positioning method. This coarse estimate may be utilized to determine a likely set of satellites from which a respective mobile device may receive signals. In the absence of a location estimate or in scenarios having a location estimate with a large uncertainty, the likely set of measurable satellites may be quite large. Further, each of these satellites may not be measurable (e.g., the satellite is no longer visible, etc.). If satellites are included in the assistance data that are not measurable by the mobile device, then the mobile device will waste time and considerable power attempting to acquire measurements for the satellite. Further, signaling methods often limit the number of satellites for which signals may be provided.
  • the signal received from each of the satellites may not necessarily result in an accurate position estimation of the handset or mobile device.
  • the quality of a position estimate largely depends upon two factors: satellite geometry, particularly, the number of satellites in view and their spatial distribution relative to the user, and the quality of the measurements obtained from satellite signals. For example, the larger the number of satellites in view and the greater the distances therebetween, the better the geometry of the satellite constellation may be. Further, the quality of measurements may be affected by errors in the predicted ephemeris of the satellites, instabilities in the satellite and receiver clocks, ionospheric and tropospheric propagation delays, multipath, receiver noise and RF interference.
  • a user with a GPS receiver obtains code-phase ranges with respect to a plurality of satellites in view, without consulting with any reference station, or where the user is at an unknown location, the user may be limited in methods to reduce the errors or noises in the ranges or even determine a position calculation.
  • an embodiment of the present subject matter provides a method for determining a set of satellites for which assistance data may be provided to a wireless device.
  • the method comprises determining a boundary for an approximate area in which the wireless device is located and determining one or more sets of satellites as a function of the boundary.
  • An optimum set of satellites may then be determined from the one or more sets of satellites as a function of the visibility of the one or more sets of satellites at predetermined points substantially on the boundary.
  • Another embodiment of the present subject matter may provide a method for determining a set of satellites for which assistance data may be provided to a wireless device.
  • the method comprises determining a boundary for an approximate area in which the wireless device is located and determining one or more sets of satellites as a function of the boundary. An optimum set of satellites may then be determined from the one or more sets of satellites as a function of the dilution of precision ("DOP") of the one or more sets of satellites at predetermined points substantially on the boundary.
  • DOP dilution of precision
  • a further embodiment of the present subject matter provides a method for determining the location of a wireless device.
  • the method comprises the steps of determining a boundary for an approximate area in which the wireless device is located, determining one or more sets of satellites as a function of the boundary, and determining an optimum set of satellites from the one or more sets of satellites as a function of the visibility of the one or more sets of satellites at predetermined points substantially on the boundary.
  • Assistance data may be transmitted to the device, the assistance data including information from the optimum set of satellites, and a location of the wireless device may be determined from the information.
  • An additional embodiment of the present subject matter provides a method for determining the location of a wireless device.
  • the method may comprise determining a boundary for an approximate area in which the wireless device is located, determining one or more sets of satellites as a function of the boundary, and determining an optimum set of satellites from the one or more sets of satellites as a function of the DOP of the one or more sets of satellites at predetermined points substantially on the boundary.
  • Assistance data may be transmitted to the device, the assistance data including information about the optimum set of satellites, and a location of the wireless device may be determined from the information.
  • One embodiment of the present subject matter may provide a system for determining a set of satellites for which assistance data may be provided to a wireless device.
  • the system may comprise circuitry for determining a boundary for an approximate area in which a wireless device is located and circuitry for determining one or more sets of satellites as a function of the boundary.
  • the system may further comprise circuitry for determining an optimum set of satellites from the one or more sets of satellites as a function of a satellite selection function at predetermined points substantially on the boundary.
  • Figure 1 is a schematic representation of a constellation of GPS satellites.
  • Figure 2 is an algorithm according to one embodiment of the present subject matter.
  • Figure 3 is an algorithm according to another embodiment of the present subject matter.
  • Figure 4 is a schematic representation for implementing one embodiment of the present subject matter.
  • A-GPS Assisted GPS
  • the disclosure relates to a mobile appliance or device and a location determining system using satellite signals and/or measurements of these satellite signals.
  • Exemplary devices may include, but are not limited to, a cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.
  • the satellites may be considered as part of a Global Navigation Satellite System ("GNSS”), such as, but not limited to, the U.S. Global Positioning System (“GPS"). While the following description references the GPS system, this in no way should be interpreted as limiting the scope of the claims appended herewith.
  • GNSS Global Navigation Satellite System
  • GPS Global Positioning System
  • GNSS systems operate, for the purposes of this disclosure, similarly to GPS, such as, but not limited to, the European Satellite project, Galileo; the Russian satellite navigation system, GLONASS; the Japanese Quasi-Zenith Satellite System (“QZSS”), and the Chinese satellite navigation and positioning system called Beidou (or Compass). Therefore, references in the disclosure to GPS and/or GNSS, where applicable, as known to those of skill in the art, apply to the above-listed GNSS systems as well as other GNSS systems not listed above.
  • GPS and/or GNSS where applicable, as known to those of skill in the art, apply to the above-listed GNSS systems as well as other GNSS systems not listed above.
  • TTFF time to forwarding assistance data from an exemplary communications network to assist in locking onto or acquiring satellites quickly.
  • A-GPS devices may include, but are not limited to, a cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver. These devices may provide satellite measurements back to a location determining system to perform a position calculation.
  • Exemplary network elements that supply the assistance data and/or perform the position calculation may be a location determining system such as a Mobile Location Center (“MLC”), location information server or system (“LIS”), or other comparable network element.
  • MLC Mobile Location Center
  • LIS location information server or system
  • the location determining system may generally be a node in a wireless network that performs the location of a mobile device.
  • Typical A-GPS information includes data for determining a GPS receiver's approximate position, time synchronization mark, satellite ephemerides, and satellite dopplers. Different A-GPS services may omit some of these parameters; however, another component of the supplied information may be the identification of the satellites for which a device or GPS receiver should search.
  • the MLC generally determines this information utilizing an approximate location of the device. Conventionally, this approximate location is the location of the cell tower serving the device. The MLC may then supply the device with the appropriate A-GPS assistance data for the set of satellites in view from this conventional location.
  • This typical process performs well when the approximate location possesses a small uncertainty, such as several hundred kilometers or less in the case with present cellular technology, since the visible satellites for a device generally do not change significantly over these several hundred kilometers.
  • the approximate location may, however, possess a larger uncertainty, such as, but not limited to, five hundred, one thousand or more kilometers.
  • An initial uncertainty area may come from an approximate location that may not be based on a cell identification but may be a function of an Mobile Country Code ("MCC”), Mobile Network Code (“MNC”), and/or an Area-Identification (“Area-ID”) resulting in a much larger region than a cell.
  • MCC Mobile Country Code
  • MNC Mobile Network Code
  • Area-ID Area-Identification
  • the Area-ID would be a location area code (“LAC”).
  • LAC Location area code
  • UTRAN UMTS Terrestrial Radio Access Network
  • RNC-ID Radio Network Controller- Identification
  • DOP dilution of precision
  • Embodiments of the present subject matter allow a communications network to supply appropriate assistance data when the approximate location of a device is unknown or cannot be determined by utilizing the boundary of a predetermined region or area and/or the boundary of the communications network to determine satellites in view.
  • While an alternate implementation of the present subject matter would provide a device with assistance data for all satellites, network protocols generally limit the number of satellites that an exemplary MLC may provide assistance data for (e.g. , Radio Resources Location Services Protocol ("RRLP”) and Positioning Calculation Application Part (“PCAP") protocol allow a maximum of 16 satellites).
  • RRLP Radio Resources Location Services Protocol
  • PCAP Positioning Calculation Application Part
  • GPS receiver hardware generally has a limited number of channels (often 12) on which it can search for satellites in parallel. Therefore, embodiments of the present subject matter may select satellites for assistance data as a function of probability and distribution and may also thin or prune such satellites as a function of their respective proximity to other satellites. It is thus an aspect of embodiments of the present subject matter to provide pertinent assistance data when the initial location uncertainty is large. This may then improve the yield and accuracy of a resulting location fix.
  • Various scenarios where embodiments of the present subject matter may be employed may be, but are not limited to, when the location of the device or handset is unknown and assistance data is requested by an A-GPS handset, e.g., when a new cell is added or renamed or when an MLC is serving a network where the MLC possesses no knowledge of the individual cell locations (such as a bureau type operation where the MLC is serving several operators in one country without details of the specific cells).
  • the device or handset may not receive assistance data for critical satellites, and the resulting location of the device may be poor (i.e., a low DOP) or a location may not be calculated at all.
  • embodiments of the present subject matter may consider the perimeter of the area or region in which the device or handset is located. This may be a location having a large uncertainty or in the case where the boundary is unknown, the location may be a city, municipality, state, country or continent.
  • a series of points around the perimeter of the boundary of an area may be selected and the satellites in view from these points are determined. Additionally, as the number of visible satellites does not generally change within 100 km of a defined point, then any one or more of the series of points may be optimized and/or extrapolated to be this distance within the boundary to thereby reduce the number of points calculated.
  • visible satellites from a defined region may be determined and/or culled if there are more than the maximum number allowed by a respective protocol (e.g., RRLP, PCAP, etc.), or if it is known that the handsets have an upper limit to the number of satellites for which they may search, e.g., they possess a fixed number of channels.
  • a respective protocol e.g., RRLP, PCAP, etc.
  • Exemplary methods to cull or reduce satellites may include, but are not limited to, reducing satellites at elevations less than a predetermined threshold on the horizon, reducing or thinning adjacent satellites as a function of the distance therebetween, and/or reducing or thinning satellites having a high altitude (e.g., if altitude accuracy is of a lower importance).
  • satellites may be reduced by determining the position of any number or all of the satellites in a complete set in earth-centered earth fixed ("ECEF") coordinates and determining a distance between each satellite in the set.
  • An exemplary distance may be, but is not limited to, a straight line distance, etc.
  • satellites may be reduced or removed from the set having a sum of the distances to any one or plural satellites that is at or below a predetermined minimum threshold. Of course, this process may be iteratively continued and/or the predetermined threshold adjusted until a sufficient number of satellites have been removed.
  • the boundary may define a serving area of a base station serving the mobile device.
  • the boundary may also define an approximate area of a communications network or an area or region such as, but not limited to, city, municipality, county, state, country, continent, or other area or polygon defined as a function of MCCs, MNCs and/or Area-IDs, such as LACs and RNC-IDs.
  • the perimeter or boundary of the area may be quantified as the vertices of a polygon or may be any other type of shape such as an ellipse or a bounding box.
  • the satellites visible from this boundary may then be collated into a list of satellites visible from the coverage area. This may be readily illustrated utilizing the following relationship:
  • a represents a maximum number of satellites that can be sent to a mobile device
  • b represents a number of satellites visible in the initial uncertainty area
  • n represents a number of satellites that should be removed from a set of satellites delivered to a respective A-GPS capable device.
  • a leave-n-out algorithm may be applied to the complete set of satellites to select a subset of satellites resulting in an optimum solution to an exemplary satellite selection function.
  • the satellite selection function may thus be determined for the following sets of satellites:
  • a satellite set may be selected that produces an optimum result.
  • an exemplary satellite selection function may be to maximize the number of satellites in view for each satellite set. This function, determined for each satellite set, is provided below in Equation (2) and may be determined for each set of satellites generated by the leave-r ⁇ -out process.
  • the optimum set of satellites may be the set that maximizes the above function in Equation (2), that is, the set that results in the highest value.
  • noSatsInView' represents a number of satellites visible for each point (i) selected substantially on the boundary of the initial uncertainty area.
  • the number of satellites for the point (i) may be equal to the number of satellites in view.
  • the number of satellites may be set to zero because a valid location may not be calculated with the number of satellites in view; however, it is possible that when a two-dimensional fix is acceptable, the 4 in Equation (2) may substituted with a 3.
  • An alternative satellite selection function may be to determine the DOP at each point ( ⁇ ) and minimize the function across each set of satellites as illustrated by the following relationship:
  • a DOP may be determined at each point (z) selected around the boundary of the initial location area and the function evaluated. The set of satellites resulting in the lowest sum of the DOP may then be selected as an optimum set.
  • Figure 2 is an algorithm 200 according to one embodiment of the present subject matter.
  • a boundary for an approximate area in which the wireless device is located may be determined.
  • the boundary may define a serving area of a base station serving the wireless device.
  • the boundary may also define an approximate area of a communications network or an area or region such as, but not limited to, city, municipality, county, state, country, or continent.
  • An exemplary device may be, but is not limited to, a cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.
  • one or more sets of satellites may be determined as a function of the boundary.
  • the satellites may be a part of a GNSS such as, but not limited to, GPS, Galileo system, GLONASS system, QZSS, Beidou satellite system, Compass satellite system, and combinations thereof.
  • a GNSS such as, but not limited to, GPS, Galileo system, GLONASS system, QZSS, Beidou satellite system, Compass satellite system, and combinations thereof.
  • an optimum set of satellites may be determined from the one or more sets of satellites as a function of the visibility of the one or more sets of satellites at predetermined points substantially on the boundary.
  • a first number of satellites that can be provided to the wireless device may be determined and at step 224, a second number of satellites visible from the approximate area may be determined.
  • a third number of satellites to be removed from the one or more sets of satellites may be determined and at step 228, the one or more sets of satellites may then be determined as a function of the first, second and third numbers.
  • an optimum set of satellites may be determined by maximizing the number of satellites in view from each of the one or more predetermined points.
  • assistance data may then be transmitted to an exemplary device in step 240 where the assistance data includes information from the optimum set of satellites.
  • the location of the wireless device may then be determined from the information.
  • Figure 3 is another algorithm 300 according to an embodiment of the present subject matter.
  • a boundary for an approximate area in which the wireless device is located may be determined.
  • the boundary may define a serving area of a base station serving the wireless device.
  • the boundary may also define an approximate area of a communications network or an area or region such as, but not limited to, city, municipality, county, state, country, or continent.
  • An exemplary device may be, but is not limited to, a cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.
  • one or more sets of satellites may be determined as a function of the boundary.
  • the satellites may be a part of a GNSS such as, but not limited to, GPS, Galileo system, GLONASS system, QZSS, Beidou satellite system, Compass satellite system, and combinations thereof.
  • a GNSS such as, but not limited to, GPS, Galileo system, GLONASS system, QZSS, Beidou satellite system, Compass satellite system, and combinations thereof.
  • an optimum set of satellites may be determined from the one or more sets of satellites as a function of the DOP of the one or more sets of satellites at predetermined points substantially on the boundary.
  • a first number of satellites that can be provided to the wireless device may be determined and at step 324, a second number of satellites visible from the approximate area may be determined.
  • a third number of satellites to be removed from the one or more sets of satellites may be determined and at step 328, the one or more sets of satellites may then be determined as a function of the first, second and third numbers.
  • an optimum set of satellites may be determined by minimizing the sum of the DOP at each of the one or more predetermined points.
  • assistance data may then be transmitted to an exemplary device in step 340 where the assistance data includes information from the optimum set of satellites.
  • the location of the wireless device may then be determined from the information.
  • FIG. 4 is a schematic representation for implementing one embodiment of the present subject matter.
  • a satellite system 410 communicates with a ground system 420.
  • the ground system 420 may include a cellular network having a location center 421.
  • the location center 421 may be an MLC, LIS or a central office configured to communicate with a telecommunication network 422 and at least one base station 423.
  • a device 424 communicates with the base station 423 to acquire GPS assistance data.
  • the location center 421 may or may not receive a preliminary estimate of the receiver's location or boundary thereof on the basis of the receiver's cell site or other area, such as the boundary of the communications network or an area or region such as, but not limited to, city, municipality, county, state, country, or continent.
  • the location center 421 may also determine a plurality of satellites as a function of this boundary or region. This information may then be transmitted or relayed to the mobile receiver and utilized for location determination.
  • the location center 421 may also receive satellite information from GPS satellites.
  • the satellite information may include the satellite's broadcast ephemeris information of the broadcasting satellite or that of all satellites or that of selected satellites.
  • the location center 421 may relay the information back to the device 424 or use the information, either singularly or along with some preliminary estimation of the device's location, to assist the device in a geographic location determination.
  • any one or plural steps illustrated in Figures 2 and 3 may be implemented at the location center 421 and communicated to the device 424.
  • the estimated location of the device 424 may also be determined as a function of additional signals provided by the network 422.
  • Exemplary devices may be, but are not limited to, a cellular device, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.
  • Figures 1-4 a method and system for selecting optimal satellites for A-GPS location of a device and for providing assistance data for A-GPS location of devices in a wireless network or other region are herein described.

Landscapes

  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Position Fixing By Use Of Radio Waves (AREA)
  • Radio Relay Systems (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

L'invention porte sur un système et un procédé de détermination d'un ensemble de satellites pour lequel les données d'aide peuvent être fournies à un dispositif sans fil. Une frontière, pour une zone approximative dans laquelle le dispositif sans fil est localisé, peut être déterminée, et un ou plusieurs ensembles de satellites peuvent être déterminés en tant que fonction de la frontière. Un ensemble optimum de satellites issus du ou des ensembles de satellites peut ensuite être déterminé par application d'une fonction de sélection de satellite sur le ou les ensembles de satellites en des points prédéterminés sensiblement sur la frontière.
PCT/US2009/069709 2009-01-06 2009-12-29 Procédé et système de sélection de satellites optimaux pour une localisation par a-gps de combinés dans des réseaux sans fil WO2010080675A2 (fr)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
US14273809P 2009-01-06 2009-01-06
US61/142,738 2009-01-06
US12/392,400 2009-02-25
US12/392,400 US9250330B2 (en) 2007-12-07 2009-02-25 Method and system for selecting optimal satellites for A-GPS location of handsets in wireless networks
US12/395,803 US7928903B2 (en) 2007-12-07 2009-03-02 Method and system for selecting optimal satellites for A-GPS location of handsets in wireless networks
US12/395,803 2009-03-02

Publications (2)

Publication Number Publication Date
WO2010080675A2 true WO2010080675A2 (fr) 2010-07-15
WO2010080675A3 WO2010080675A3 (fr) 2010-10-21

Family

ID=42317087

Family Applications (2)

Application Number Title Priority Date Filing Date
PCT/US2009/069709 WO2010080675A2 (fr) 2009-01-06 2009-12-29 Procédé et système de sélection de satellites optimaux pour une localisation par a-gps de combinés dans des réseaux sans fil
PCT/US2009/069717 WO2010080676A2 (fr) 2009-01-06 2009-12-29 Procédé et système pour satellites optimaux pour la localisation gps assisté de combinés dans des réseaux sans fil

Family Applications After (1)

Application Number Title Priority Date Filing Date
PCT/US2009/069717 WO2010080676A2 (fr) 2009-01-06 2009-12-29 Procédé et système pour satellites optimaux pour la localisation gps assisté de combinés dans des réseaux sans fil

Country Status (1)

Country Link
WO (2) WO2010080675A2 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102390410A (zh) * 2011-06-23 2012-03-28 中国北车股份有限公司大连电力牵引研发中心 一种基于北斗系统的车辆监控系统及其控制方法
CN102841363A (zh) * 2012-08-24 2012-12-26 北斗天汇（北京）科技有限公司 车辆导航监控系统
CN103439721A (zh) * 2013-08-14 2013-12-11 东莞市科维电子科技有限公司 一种北斗与gps卫星双模导航系统及其导航方法
CN103700271A (zh) * 2013-12-23 2014-04-02 天津七六四通信导航技术有限公司 应用于车辆调配的北斗用户机系统
WO2014145954A1 (fr) * 2013-03-15 2014-09-18 Moontunes, Inc. Systèmes et procédés pour positionner un dispositif de liaison montante de satellite
CN109697877A (zh) * 2019-02-18 2019-04-30 河北省交通规划设计院 基于北斗高精定位的车路协同方法及系统

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11493640B2 (en) 2020-05-29 2022-11-08 Trimble Inc. Multi-staged pipelined GNSS receiver

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6353738B1 (en) * 1998-11-30 2002-03-05 Hughes Electronics Corporation Method for implementing a terminal-to-terminal call with an optimal use of radio resources in a mobile satellite system
US20070236387A1 (en) * 2005-12-29 2007-10-11 Alcatel Lucent Method of optimization of processing of location data in the presence of a plurality of satellite positioning constellations
KR20080108419A (ko) * 2006-01-10 2008-12-15 퀄컴 인코포레이티드 글로벌 네비게이션 위성 시스템

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3210502B2 (ja) * 1993-09-27 2001-09-17 アルパイン株式会社 衛星航法による測位方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6353738B1 (en) * 1998-11-30 2002-03-05 Hughes Electronics Corporation Method for implementing a terminal-to-terminal call with an optimal use of radio resources in a mobile satellite system
US20070236387A1 (en) * 2005-12-29 2007-10-11 Alcatel Lucent Method of optimization of processing of location data in the presence of a plurality of satellite positioning constellations
KR20080108419A (ko) * 2006-01-10 2008-12-15 퀄컴 인코포레이티드 글로벌 네비게이션 위성 시스템

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102390410A (zh) * 2011-06-23 2012-03-28 中国北车股份有限公司大连电力牵引研发中心 一种基于北斗系统的车辆监控系统及其控制方法
CN102841363A (zh) * 2012-08-24 2012-12-26 北斗天汇（北京）科技有限公司 车辆导航监控系统
WO2014145954A1 (fr) * 2013-03-15 2014-09-18 Moontunes, Inc. Systèmes et procédés pour positionner un dispositif de liaison montante de satellite
CN103439721A (zh) * 2013-08-14 2013-12-11 东莞市科维电子科技有限公司 一种北斗与gps卫星双模导航系统及其导航方法
CN103700271A (zh) * 2013-12-23 2014-04-02 天津七六四通信导航技术有限公司 应用于车辆调配的北斗用户机系统
CN109697877A (zh) * 2019-02-18 2019-04-30 河北省交通规划设计院 基于北斗高精定位的车路协同方法及系统

Also Published As

Publication number Publication date
WO2010080676A3 (fr) 2010-10-14
WO2010080675A3 (fr) 2010-10-21
WO2010080676A2 (fr) 2010-07-15

Similar Documents

Publication Publication Date Title
US7928903B2 (en) Method and system for selecting optimal satellites for A-GPS location of handsets in wireless networks
US7916071B2 (en) System and method for determining a reference location of a mobile device
US7800530B2 (en) Method and system for providing assistance data for A-GPS location of handsets in wireless networks
US7986266B2 (en) Method and system for selecting optimal satellites in view
US8467805B2 (en) System and method for determining a reference location using cell table data mining
US8217832B2 (en) Enhancing location accuracy using multiple satellite measurements based on environment
US20100127923A1 (en) System and method for determining falsified satellite measurements
US8378888B2 (en) System and method for determining the location of a mobile device
WO2010059440A2 (fr) Système et procédé pour détection côté serveur de mesures satellites falsifiées
WO2010059439A2 (fr) Système et procédé permettant de déterminer l'emplacement géographique falsifié d'un dispositif mobile
WO2010080675A2 (fr) Procédé et système de sélection de satellites optimaux pour une localisation par a-gps de combinés dans des réseaux sans fil
US20160033650A1 (en) Method and system for selecting optimal satellites for a-gps location of handsets in wireless networks
US20100149031A1 (en) System and method for determining forged radio frequency measurements
US7999730B2 (en) System and method for providing GNSS assistant data without dedicated receivers

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09838024

Country of ref document: EP

Kind code of ref document: A2

NENP Non-entry into the national phase in:

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09838024

Country of ref document: EP

Kind code of ref document: A2