Combining GPS with TOA/TDOA of cellular signals to locate terminal
First Claim
1. A position location system for determining a geographic position comprising:
- a global positioning system (GPS) receiver that receives global positioning system satellite signals from a plurality of global positioning system satellites, and calculates the geographic position using the received global positioning system satellite signals;
a mobile cellular portion that receives cellular position signals that do not contain data in a GPS-like format from a plurality of cellular network base stations and calculates the geographic position using the received cellular position signals; and
a central processor connected to said global positioning system receiver and to said mobile cellular portion, wherein said central processor control operation of said global positioning system receiver and said mobile cellular receiver.
7 Assignments
0 Petitions
Accused Products
Abstract
Aspects of global positioning system (GPS) technology and cellular technology are combined in order to provide an effective and efficient position location system. In a first aspect of the invention, a cellular network is utilized to collect differential GPS error correction data, which is forwarded to a mobile terminal over the cellular network. The mobile terminal receives this data, along with GPS pseudoranges using a GPS receiver, and calculates its position using this information. According to a second aspect, when the requisite number of GPS satellites are not in view of the mobile terminal, then a GPS pseudosatellite signal, broadcast from a base station of the cellular network, is received by the mobile terminal and processed as a substitute for the missing GPS satellite signal. A third aspect involves calculating position using GPS when the requisite number of GPS satellites are in view of a GPS receiver, but when the requisite number of GPS satellites are not in view of the GPS receiver, then position is calculated using the cellular network infrastructure. When the requisite number of GPS satellites come back into view of the GPS receiver, then position is again calculated using GPS. A fourth aspect involves using cellular signals already being transmitted from base stations to terminals in a cellular network to calculate a round trip delay, from which a distance calculation between the base station and the terminal can be made. This distance calculation substitutes for a missing GPS satellite signal.
528 Citations
17 Claims
-
1. A position location system for determining a geographic position comprising:
-
a global positioning system (GPS) receiver that receives global positioning system satellite signals from a plurality of global positioning system satellites, and calculates the geographic position using the received global positioning system satellite signals; a mobile cellular portion that receives cellular position signals that do not contain data in a GPS-like format from a plurality of cellular network base stations and calculates the geographic position using the received cellular position signals; and a central processor connected to said global positioning system receiver and to said mobile cellular portion, wherein said central processor control operation of said global positioning system receiver and said mobile cellular receiver. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method for determining a geographic position of a mobile terminal comprising the steps of:
-
receiving global positioning system satellite signals from a plurality of global positioning system satellites; receiving a plurality of cellular position signals; calculating the geographic position of the mobile terminal using said received global positioning system satellite signals when a requisite number of the plurality of global positioning system satellites are in view of a global positioning system receiver; and calculating the geographic position of the mobile terminal using only said received plurality of cellular position signals when the requisite number of the plurality of global positioning system satellites are not in view of the global positioning system receiver. - View Dependent Claims (12, 13, 14, 15)
-
-
16. A method for determining a geographic position of a mobile terminal comprising the steps of:
-
receiving global positioning system satellite (GPS) signals from a plurality of global positioning system satellites; receiving a plurality of cellular position signals that do not contain data in a GPS-like format; calculating the geographic position of the mobile terminal using said received global positioning system satellite signals when a requisite number of the plurality of global positioning system satellites are in view of a global positioning system receiver; and calculating the geographic position of the mobile terminal using both said received plurality of cellular position signals and substantially all of said received global positioning system satellite signals when the requisite number of the plurality of global positioning system satellites are not in view of the global positioning system receiver.
-
-
17. A method for determining a geographic position of a mobile terminal comprising the steps of:
-
receiving global positioning system satellite (GPS) signals from a plurality of global positioning system satellites; receiving a plurality of cellular position signals that do not contain data in a GPS-like format; and calculating the geographic position of the mobile terminal using substantially all of the received global positioning system satellite signals and substantially all of said received plurality of cellular position signals.
-
Specification