Positioning system

• US 7,277,050 B2
• Filed: 02/17/2004
• Issued: 10/02/2007
• Est. Priority Date: 02/28/2003
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Ikeda, Masayuki
• Primary Examiner(s): Tarcza; Thomas H.
• Assistant Examiner(s): Mull; Fred H
• Application Number:
  US10/780,288
• Publication Number:
  US 20040212531A1
• Time in Patent Office: 1,323 Days
• Field of Search: 34235706-35707, 342/357.09, 342/357.1, 342/357.14, 342/357.15, 342463-464, 342/465
• US Class Current: 342/357.43
• CPC Class Codes: G01S 11/08 using synchronised clocks
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/06 employing an initial estimate of the location of the receiver as aiding data or in generating aiding data
• CPC Class Codes: G01S 19/12 wherein the cooperating elements are telecommunication base stations
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A positioning system is provided having a first signal source for originating synchronous signals, and a second signal source for originating a signal which is not synchronous with the signal from the first signal source. The system determines, based on a signal propagation time and signal propagation speed from the first or second signal source, the distance to this signal source so as to determine a position of a receiving point.

Claims

1. A positioning system that determines a position of a positioning terminal, the system including a plurality of first signal sources each emitting a respective first signal, and one or more second signal sources each emitting a respective second signal, the first signals being synchronous with a reference time and the second signals being non-synchronous with the first signals, that, based on a signal propagation time and signal propagation speed of the first signals, determines a distance from the positioning terminal, said positioning system comprising:

a measurement device that receives the first signals from the first signal sources to determine a position P of the measurement device and a time of measurement when the measurement device receives the first signals and that, based on the time of measurement, measures a receiving time (TR), based on the reference time, of a predetermined event of the second signals;

a control device that determines a signal propagation time (t) between the measurement device and one of the second signal sources by calculating a relative distance |P−

Q| between the measurement device and the one second signal source based on the position P measured by the measurement device and a position Q of the one second signal source and by dividing the resulting distance by the signal propagation speed, and determining a time (TT), based on the reference time, at which the one second signal source originates the predetermined event by solving TR-t;

the positioning terminal having a receiving device that receives the signals from the first and second signal sources; and

a communication device that communicates between the control device and the positioning terminal,

wherein the positioning terminal uses the time TT to limit a search for the signals from the first signal sources, and uses the signals from the first signal sources to determine the position of the positioning terminal;

wherein the measurement device further comprises a mobile terminal in good condition;

wherein the position P of the measurement device can be determined without accurate time information; and

wherein the measurement device measures P and TR and voluntarily reports the measured P and TR to the control device.

2. The positioning system according to claim 1, wherein the first signal sources further comprise GPS satellites.

3. The positioning system according to claim 1, wherein the second signal sources further comprise base stations of a mobile communication network.

4. The positioning system according to claim 1, wherein the measurement device measures P and TR according to a request from the control device in the same mobile communication network to report the measured P and TR to the control device.

5. A positioning system according to claim 1, wherein the second signal sources further comprise television broadcast stations.

6. The positioning system according to claim 1, wherein the second signal sources further comprise television broadcast stations.

7. A positioning system that determines a position of a positioning terminal, the system including a plurality of first signal sources each emitting a respective first signal, and one or more second signal sources each emitting a respective second signal, the first signals being synchronous with a reference time and the second signals being non-synchronous with the first signals, that, based on a signal propagation time and signal propagation speed of at least one of the first and second signal sources determines a position of the positioning terminal, said positioning system comprising:

a measurement device associated with each second signal source that receives the first signals from the first signal sources to determine a position P of the measurement device and a time of measurement when the measurement device receives the first signals and that, based on the time of measurement, measures a receiving time (TR), based on the reference time, of a predetermining event of the second signals;

a control device that determines a signal propagation time (t) between the measurement device and its associated second signal source by calculating a relative distance |P−

Q| between the measurement device and its associated second signal source based on the position P measured by the measurement device and a position Q of the second signal source and by dividing the resulting distance by the signal propagation speed, and that determines a time (TT), based on the reference time, at which the second signal source originates the predetermined event by solving TR-t;

the positioning terminal having a receiving device that receives the signals from the first and second signal sources; and

a communication device that communicates between the control device and the positioning terminal,

wherein the positioning terminal uses the time TT as a reference to receive the first signals and receives the first and second signals to determine the position of the positioning terminal;

wherein the measurement device further comprises a mobile terminal in good condition;

wherein the position P of the measurement device can be determined without accurate time information; and

wherein the measurement device measures P and TR and voluntarily reports the measured P and TR to the control device.

8. The positioning system according to claim 7, wherein the first signal sources further comprise GPS satellites.

9. The positioning system according to claim 7, wherein the second signal sources further comprise base stations of a mobile communication network.

10. The positioning system according to claim 7, wherein the measurement device measures P and TR according to a request from the control device in the same network to report the measured P and TR to the control device.

11. A positioning terminal that determines a position of the positioning terminal, the positioning terminal including a receiving device that receives signals from a plurality of first signal sources each emitting a respective first signal and one or more second signal sources each emitting a respective second signal, the first signals being synchronous with a reference time and the second signals being non-synchronous with the first signals, that, based on a signal propagation time and signal propagation speed of the first signals, determines a distance from the positioning terminal, said positioning terminal comprising:

a calculation device that calculates TT=TR−

|P−

Q|/c;

wherein the P is a position of a measurement device when the measurement device received the first signals from the first signal sources;

the Q is a position of the one second signal source;

the |P−

Q| is a relative distance between the measurement device and the one second source;

the c is a signal propagation speed;

the TR is a receiving time, based on the reference time, when the measurement device received a predetermined event of the second signals at the position P;

wherein the positioning terminal uses the time TT to limit a search for the signals from the first signal sources, and uses the signals from the first signal sources to determine the position of the positioning terminal;

wherein the measurement device further comprises a mobile terminal in good condition;

wherein the position P of the measurement device can be determined without accurate time information; and

wherein the measurement device measures P and TR and voluntarily reports the measured P and TR to a control device in the same mobile communication network.

12. The positioning terminal according to claim 11, wherein the first signal sources further comprise GPS satellites.

13. The positioning terminal according to claim 11, wherein the second signal sources further comprise base stations of a mobile communication network.

14. The positioning terminal according to claim 11, wherein the measurement device measures P and TR according to a request from the control device in the same mobile communication network to report the measured P and TR to the control device.

15. The positioning terminal according to claim 11, wherein the second signal sources further comprise television broadcast stations.

16. The positioning terminal according to claim 11, wherein the second signal sources further comprise television broadcast stations.

17. A positioning terminal that determines a position of the positioning terminal, the positioning terminal including a receiving device that receives signals from a plurality of first signal sources each emitting a respective first signal and one or more second signal sources each emitting a respective second signal, the first signals being synchronous with a reference time and the second signals being non-synchronous with the first signals, for, based on a signal propagation time and signal propagation speed of at least one of the first and second sources determines a position of the positioning terminal, said positioning terminal comprising:

a calculation device that calculates TT=TR−

|P−

Q|/c;

wherein the P is a position of a measurement device when the measurement device received the first signals from the first signal sources;

the Q is a position of the one second signal source;

the |P−

Q| is a relative distance between the measurement device and the one second source;

the c is a signal propagation speed;

the TR is a receiving time, based on the reference time, when the measurement device received a predetermined event of the second signals at the position P;

wherein the positioning terminal uses the time TT as a reference to receive the signals from the first signal sources and receives the first and second signals to determine the position of the positioning terminal;

wherein the measurement device further comprises a mobile terminal in good condition;

wherein the position P of the measurement device can be determined without accurate time information; and

wherein the measurement device measures P and TR and voluntarily reports the measured P and TR to a control device in the same mobile communication network.

18. The positioning terminal according to claim 17, wherein the first signal sources further comprise GPS satellites.

19. The positioning terminal according to claim 17, wherein the second signal sources further comprise base stations of a mobile communication network.

20. The positioning terminal according to claim 17, wherein the measurement device measures P and TR according to a request from the control device in the same network to report the measured P and TR to the control device.