System and method for locating mobile device in wireless communication network

Abstract

A method is provided for determining a location of a mobile device in a wireless network. The method includes receiving global navigation satellite system (GNSS) measurements from the mobile device, and receiving terrestrial measurements from corresponding transceivers in the wireless network, each terrestrial measurement indicating a distance between the corresponding transceivers and the mobile device. The method further includes selecting at least one terrestrial measurement having an uncertainty value within a predetermined accuracy threshold. The location of the mobile device is determined as a function of the GNSS measurements and the selected terrestrial measurement.

1 . A method for determining a location of a mobile device in a wireless network, the method comprising:
 receiving a plurality of global navigation satellite system (GNSS) measurements for the mobile device;   receiving a plurality of terrestrial measurements from a corresponding plurality of transceivers in the wireless network, each terrestrial measurement indicating a distance between the corresponding transceiver and the mobile device;   selecting at least one terrestrial measurement having an uncertainty value within a predetermined accuracy threshold; and   determining the location of the mobile device as a function of the plurality of GNSS measurements and the at least one selected terrestrial measurement.   
     
     
         2 . The method of  claim 1 , wherein the plurality of GNSS measurements are received from the mobile device. 
     
     
         3 . The method of  claim 1 , wherein the GNSS measurements comprise measurements from one of a global positioning system (GPS), a Global Navigation Satellite System (GLONASS), Galileo system or a COMPASS Navigation Satellite System (BeiDou). 
     
     
         4 . The method of  claim 1 , wherein the plurality of terrestrial measurements comprise at least one of uplink-time difference of arrival (U-TDOA) measurements, timing advance (TA) measurements, round-trip time (RTT) measurements, enhanced observed time difference (E-OTD) measurements, angle of arrival (AoA) measurements, power of arrival (POA) measurements, WiFi measurements, and DTV signals. 
     
     
         5 . The method of  claim 2 , further comprising:
 receiving a location request to determine an estimated location of the mobile device;   determining GNSS assistance data as a function of information in the received request; and   sending the GNSS assistance data to the mobile device to obtain the GPS measurements.   
     
     
         6 . A method of determining a location of a mobile device in a wireless network, the method comprising:
 receiving a plurality of global navigation satellite system (GNSS) measurements for the mobile device;   receiving a plurality of terrestrial measurements from a corresponding plurality of transceivers in the wireless network, each terrestrial measurement indicating a distance between the corresponding transceiver and the mobile device, and a corresponding uncertainty value associated with the distance;   determining a first dilution of precision (DOP) measure corresponding to the received GNSS measurements;   determining a revised DOP measure corresponding to each terrestrial measurement combined with the GNSS measurements;   determining for each terrestrial measurement whether a product of the corresponding revised DOP measure and the corresponding uncertainty value is less than a predetermined threshold;   selecting at least one terrestrial measurement as a function of the corresponding revised DOP measure; and   determining the location of the mobile device as a function of the GNSS measurements and the selected at least one terrestrial measurement; and   wherein the selected at least one terrestrial measurement includes all terrestrial measurements having corresponding products less than the predetermined threshold.   
     
     
         7 . The method of  claim 6 , wherein the GNSS measurements comprise measurements from one of a global positioning system (GPS), a Global Navigation Satellite System (GLONASS), Galileo system or a COMPASS Navigation Satellite System (BeiDou). 
     
     
         8 . The method of  claim 6 , wherein the plurality of terrestrial measurements comprise at least one of uplink-time difference of arrival (U-TDOA) measurements, timing advance (TA) measurements, round-trip time (RTT) measurements, enhanced observed time difference (E-OTD) measurements, angle of arrival (AoA) measurements, power of arrival (POA) measurements, WiFi measurements, and DTV signals. 
     
     
         9 . A method for determining a location of a mobile device in a wireless network, the method comprising:
 providing an initial location estimate for the mobile device, the initial location estimate having a corresponding initial uncertainty area;   calculating a minimum range and a maximum range between a transceiver in the wireless network and the mobile device as a function of a given location of the transceiver and the uncertainty area of the initial location;   receiving global navigation satellite system (GNSS) measurements for the mobile device;   receiving a terrestrial measurement from the transceiver indicating a distance between the transceiver and the mobile device, and accepting the terrestrial measurement when the terrestrial measurement is between the minimum range and the maximum range; and   determining the location of the mobile device as a function of the GNSS measurements and the terrestrial measurement when the terrestrial measurement is accepted.   
     
     
         10 . The method of  claim 9 , further comprising:
 determining the location of the mobile device as a function of the GNSS measurements when the terrestrial measurement is not accepted.   
     
     
         11 . The method of  claim 9 , wherein the initial location estimate comprises a location of a base station in the wireless network serving the mobile device, and the uncertainty area comprises a coverage area of a cell corresponding to the base station. 
     
     
         12 . The method of  claim 9 , wherein the initial uncertainty area comprises one of an ellipse, a circle, an arc band or a polygon. 
     
     
         13 . The method of  claim 9 , wherein the minimum range is zero and the maximum range is a distance between the transceiver and a furthest point on an outer boundary of the initial uncertainty area when the given location of the transceiver is inside the uncertainty area. 
     
     
         14 . The method of  claim 9 , wherein the minimum range is a distance between the transceiver and a closest point on an outer boundary of the initial uncertainty area, and the maximum range is a distance between the transceiver and a furthest point on the outer boundary of the initial uncertainty area when the given location of the transceiver is outside the uncertainty area. 
     
     
         15 . The method of  claim 9 , wherein the initial uncertainty area comprises one of a WiFi hotspot or a WiMedia hotspot. 
     
     
         16 . A method for determining a location of a mobile device in a wireless network, the method comprising:
 receiving a plurality of global navigation satellite system (GNSS) measurements for the mobile device;   calculating a first location of the mobile device and a first error ellipse at a predetermined confidence level as a function of the GNSS measurements;   receiving a plurality of terrestrial measurements from a plurality of transceivers in the wireless network, each terrestrial measurement indicating a distance between the respective transceiver and the mobile device;   calculating a plurality of second locations of the mobile device and a plurality of second error ellipses at the predetermined confidence level as a function of the GNSS measurements and multiple combinations of the plurality of terrestrial measurements;   comparing the first error ellipse with each of the plurality of second error ellipses; and   determining the location of the mobile device as either the first location or one of the second locations as a function of the comparison of the first and second error ellipses.   
     
     
         17 . The method of  claim 16 , wherein the location of the mobile device is determined as the first location when the first error ellipse is smaller than each of the plurality of second error ellipses. 
     
     
         18 . The method of  claim 16 , wherein the one of the second locations is calculated as a function of the GNSS measurements and all of the plurality of terrestrial measurements.