Wireless network assisted GPS system

• US 7,532,158 B2
• Filed: 03/06/2007
• Issued: 05/12/2009
• Est. Priority Date: 04/25/2003
• Status: Active Grant

• Current Assignee: New Jersey Institute of Technology
• Original Assignee: New Jersey Institute of Technology
• Inventors: Tekinay, Sirin, Choi, Woo-Jin
• Primary Examiner(s): Phan; Dao L
• Application Number:
  US11/682,434
• Publication Number:
  US 20070159389A1
• Time in Patent Office: 798 Days
• Field of Search: 342/357.01, 342/357.06, 342/357.09, 342/357.12, 701/213, 701/215
• US Class Current: 342/357.46
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A method, apparatus, and/or system for locating mobile devices may use location information received from a mobile device to be located. Such information may include GPS-related information and/or path length information with respect to one or more signals transmitted by network elements. Such information may be augmented by information provided by one or more network elements, which information may include path length measurements based on signals transmitted from the mobile device.

Claims

1. An apparatus comprising:

a location application processor having access to GPS satellite data and configured to receive a set of GPS parameters from a mobile unit and to process the GPS parameters in view of the GPS satellite data to calculate a position of the mobile unit, wherein the location application processor is not collocated with the mobile unit.

2. The apparatus according to claim 1, wherein said location application processor is further configured to receive from said mobile unit timing and distance information received by said mobile unit from one or more base stations of a wireless network and to use said timing and distance information to assist in calculating the position of the mobile unit.

3. The apparatus according to claim 1, wherein said location application processor is further configured to collect at least three items of information, said items of information to be selected from among the group consisting of:

one or more differences in path lengths of plural signals sent from different base stations of the wireless network to the mobile unit;

one or more differences in lengths of signals sent to/from satellites from/to the GPS receiver associated with the mobile unit; and

one or more differences in path lengths of one or more signals sent from the mobile unit to plural base stations of the wireless network; and

to combine said at least three types of information to obtain a location of said mobile unit.

4. The apparatus according to claim 2, wherein said timing and distance information includes distances between said mobile unit and at least two of said base stations.

5. The apparatus according to claim 4, wherein said location application processor is configured to utilize at least one time difference of arrival equation to calculate the position of the mobile unit.

6. A method comprising:

collecting at least three items of information, said items of information to be selected from among the group consisting of;

one or more differences in path lengths of plural signals sent from different base stations of a wireless network to a mobile unit;

one or more differences in lengths of signals sent to/from satellites from/to a GPS receiver collocated with the mobile unit; and

one or more differences in path lengths of one or more signals sent from the mobile unit to plural base stations of the wireless network;

wherein at least one of the items of information collected comprises a GPS parameter obtained by a GPS receiver collocated with the mobile unit, and wherein said collecting is performed at a location not collocated with said mobile unit; and

combining said at least three types of information to obtain a location of said mobile unit.

7. The method according to claim 6, wherein said collecting comprises:

obtaining at least one of said one or more differences in path lengths of one or more signals sent from the mobile unit to plural base stations of the wireless network from said mobile unit.

8. The method according to claim 6, wherein said combining comprises:

solving a system of simultaneous equations to obtain the location of said mobile unit.

9. The method according to claim 8, wherein said simultaneous equations are selected from the group consisting of GPS equations and time difference of arrival equations.

10. The method according to claim 8, wherein said solving includes employing a technique selected from the group consisting of:

closed form solution;

iteration based on linearization; and

Kalman filtering.

11. A system comprising:

a base station to be disposed in a wireless communication network; and

a location application processor, to be coupled to said base station, the location application processor having access to GPS satellite data and configured to receive a set of GPS parameters from a mobile unit and to process the GPS parameters in view of the GPS satellite data to calculate a position of the mobile unit, wherein said location application processor is not collocated with the mobile unit.

12. The system according to claim 11, wherein said location application processor is further configured to receive from said mobile unit timing and distance information received by said mobile unit from one or more base stations of the wireless network.

13. The system according to claim 11, wherein said location application processor is further configured to collect at least three items of information, said items of information to be selected from among the group consisting of:

one or more differences in path lengths of plural signals sent from different base stations of the wireless network to the mobile unit;

one or more differences in lengths of signals sent to/from satellites from/to the GPS receiver associated with the mobile unit; and

one or more differences in path lengths of one or more signals sent from the mobile unit to plural base stations of the wireless network; and

to combine said at least three types of information to obtain a location of said mobile unit.

14. The apparatus according to claim 12, wherein said timing and distance information includes distances between said mobile unit and at least two of said base stations.

15. The apparatus according to claim 14, wherein said location application processor is configured to utilize at least one time difference of arrival equation to calculate the position of the mobile unit.