POSITIONING SYSTEM

• US 20090096666A1
• Filed: 12/12/2008
• Published: 04/16/2009
• Est. Priority Date: 02/28/2003
• Status: Abandoned Application

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: IKEDA, Masayuki
• Application Number:
  US12/333,366
• Publication Number:
  US 20090096666A1
• Time in Patent Office: Days
• 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 method for providing information to a positioning terminal comprising:

receiving positional information and time information from a mobile terminal based on a positioning signal received from a satellite positioning system (SPS) satellite;

calculating a reference time based on the positional information and the time information;

receiving an information request signal from the positioning terminal; and

sending the reference time corresponding with the information request signal.

2. The method according to claim 1, wherein the positional information includes a receiving position (P) of the mobile terminal, the time information includes a receiving time (T_R) of a signal from a base station based on a measured time measured by the mobile terminal, said signal is non-synchronous with the positioning signal from the SPS satellite and is emitted at a predetermined event of the base station, and the reference time includes a time (T_T) when the predetermined event of the base station occurred, said time is calculated based on the position P and the time T_R received from the mobile terminal.

3. The method according to claim 2 further comprising calculating the time T_T from a formula T_T=T_R−

|P−

Q|/c in which a position (Q) is a position of the base station, |P−

Q| is a relative distance between the mobile terminal and the position of the base station, and c is a signal propagation speed.

4. The method according to claim 2 further comprising calculating the time T_T based on the position P and the time T_R which is measured at a plurality of different locations by the same mobile terminal.

5. The method according to claim 2, further comprising calculating the time T_T based on the position P and the time T_R measured by a plurality of mobile terminals.

6. The method according to claim 4 further comprising calculating the time T_T based on a plurality of the position P and the time T_R using a least-square method.

7. The method according to claim 5 further comprising calculating the time T_T based on a plurality of the position P and the time T_R using a least-square method.

8. The method according to claim 5 further comprising:

receiving a coverage cell report containing a coverage cell from the plurality of mobile terminals, at either a power activation, a predetermined time interval or a predetermined timing;

generating a list of mobile terminals that exist within the covered cell based on the coverage cell report; and

requesting the position P and the time T_R from the mobile terminals based on the list at either a predetermined time interval or a predetermined timing.

9. The method according to claim 5 further comprising receiving the position P and the time T_R sent from the plurality of mobile terminals at either a predetermined time interval or a predetermined timing.

10. An apparatus for providing information to a positioning terminal comprising:

a receiver that receives positional information and time information from a mobile terminal based on a positioning signal received from a satellite positioning system (SPS) satellite;

a calculator that calculates a reference time based on the positional information and the time information;

a transmitter that receives an information request signal from the positioning terminal and sends the reference time corresponding with the information request signal.

11. The positioning apparatus according to claim 10, wherein the positional information includes a receiving position (P) of the mobile terminal, the time information includes a receiving time (T_R) of a signal from a base station based on the time measured by the mobile terminal, said signal is non-synchronous with the positioning signal from the SPS satellite and is emitted at a predetermined event of the base station, and the reference time includes a time (T_T) when the predetermined event of the base station occurred, said time is calculated based on the position P and the time T_R received from the mobile terminal.

12. The apparatus according to claim 11, wherein the calculator calculates the time T_T using the formula, T_T=T_R−

|P−

Q|/c, in which a position (Q) is a position of the base station, |P−

Q| is a relative distance between the mobile terminal and the position of the base station, and c is a signal propagation speed.

13. The apparatus according to claim 11, wherein, from a mobile terminal, the receiver receives sets of the position P and the time T_R respectively measured at a plurality of different locations by the same mobile terminal, and wherein the calculator calculates the time T_T based on the sets of the position P and the time T_R.

14. The apparatus according to claim 11, wherein the receiver that receives sets of the position P and the time T_R from a plurality of the mobile terminals and wherein the calculator calculates the time T_T based on the sets of the position P and the time T_R.

15. The apparatus according to claim 13, wherein the calculator calculates the time T_T based on the sets of the position P and the time T_R using a least-square method.

16. The apparatus according to claim 14, wherein the calculator calculates the time T_T based on the sets of the position P and the time T_R using a least-square method.

17. The apparatus according to claim 14 further comprising:

a report receiver that receives a coverage cell report containing a coverage cell from the plurality of the mobile terminals at either a power activation, a predetermined time interval or a predetermined timing;

a mobile terminal list generator that generates a list of mobile terminals existing within the covered cell based on the coverage cell report;

an information requester that requests the position P and the time T_R from the plurality of mobile terminals based on the list at a predetermined time interval or the predetermined timing.

18. The apparatus according to claim 14, wherein the receiver receives the position P and the time T_R sent from the plurality of mobile terminals at either a predetermined time interval or a predetermined timing.

19. A system to provide information to a positioning terminal comprising:

a receiver that receives positional information and time information from a mobile terminal based on a positioning signal received from a satellite positioning system (SPS) satellite;

a calculator that calculates a reference time based on the positional information and the time information;

a transmitter that receives an information request signal from the positioning terminal and sends the reference time corresponding with the information request signal.

20. The system according to claim 19, wherein the positional information includes a receiving position (P) of the mobile terminal, the time information includes a receiving time (T_R) of a signal from a base station based on a measured time measured by the mobile terminal, said signal is non-synchronous with the positioning signal from the SPS satellite and is emitted at a predetermined event of the base station, and the reference time includes a time (T_T) when the predetermined event of the base station occurred, said time is calculated based on the position P and the time T_R received from the mobile terminal.

21. The system according to claim 20, wherein the calculator calculates the time T_T from a formula T_T=T_R−

|P−

Q|/c in which a position (Q) is a position of the base station, |P−

Q| is a relative distance between the mobile terminal and the position of the base station, and c is a signal propagation speed.

22. The system according to claim 20, wherein the receiver receives, from a mobile terminal, sets of the position P and the time T_R which is respectively measured at a plurality of different locations by the same mobile terminal, and wherein the calculator calculates the time T_T based on the sets of the position P and the time T_R.

23. The system according to claim 20, wherein the receiver receives sets of the position P and the time T_R from a plurality of the mobile terminals, and wherein the calculator calculates the time T_T based on the sets of the position P and the time T_R.

24. The system according to claim 22, wherein the calculator calculates the time T_T based on the sets of the position P and the time T_R using a least-square method.

25. The system according to claim 23, wherein the calculator calculates the time T_T based on the sets of the position P and the time T_R using a least-square method.

26. The system according to claim 23 further comprising:

a report receiver that receives a coverage cell report containing a coverage cell from the plurality of the mobile terminals at either a power activation, a predetermined time interval or a predetermined timing;

a mobile terminal list generator that generates a list of mobile terminals existing within the covered cell based on the coverage cell report;

an information requester that requests the position P and the time T_R from the plurality of the mobile terminals based on the list at either a predetermined time interval or a predetermined timing.

27. The system according to claim 23, wherein the receiver receives the sets of the position P and the time T_R which is sent from a plurality of mobile terminals at either a predetermined time interval or a predetermined timing.

28. A positioning terminal including a satellite signal receiver receiving a positioning signal from a satellite positioning system (SPS) satellite and a base station signal receiver receiving a signal from a base station comprising:

a transmitter that sends an information request signal to an information providing apparatus where the reference time is stored, said information providing apparatus receives positional information and time information from a mobile terminal based on the positioning signal received from the SPS satellite, and calculates a reference time based on the positional information and the time information;

a reference time receiver that receives the reference time from the information providing apparatus;

an error corrector that corrects the signal from the base station based on the reference time; and

a positioning device that positions based on the positioning signal and the corrected signal from the base station.

29. The positioning terminal according to claim 28, wherein the positional information includes a receiving position (P) of the mobile terminal, wherein the time information includes a receiving time (T_R) of a predetermined event of a signal from the base station based on the time measured by the mobile terminal, said signal is non-synchronous with the positioning signal from the SPS satellite and is emitted at a predetermined event of the base station, and the reference time includes a time (T_T) when the predetermined event of the base station occurred, said time is calculated based on the position P and the time T_R received from the mobile terminal.

30. The positioning terminal according to claim 29, wherein the information providing apparatus calculates the time T_T using the formula, T_T=T_R−

|P−

Q|/c, in which a position (Q) is a position of the base station, |P−

Q| is a relative distance between the mobile terminal and the position of the base station, and c is a signal propagation speed.

31. The positioning terminal according to claim 29, wherein the satellite signal receiver receives the positioning signal from one SPS satellite, and wherein the base station signal receiver receives the signals from two or more base stations, and positions based on the positioning signal and a corrected base station signal.

32. The positioning terminal according to claim 29, wherein the base station signal receiver receives signals from at least three base stations when the satellite signal receiver is unable to receive the positioning signal from the SPS satellite and positions based on a corrected base station signal.

33. A mobile terminal including a satellite signal receiver receiving a positioning signal from a satellite positioning system (SPS) satellite and a positioning device positioning based on the positioning signal, comprising:

a base station signal receiver that receives a signal from a base station;

a measurement device that measures a receiving time (T_R) of a predetermined event of the signal received from the base station based on a predetermined time; and

a transmitter that sends positional information and a receiving time to the information providing apparatus where the positional information and the receiving time are provided to a positioning terminal, wherein the information providing apparatus calculates reference time based on the positional information and the receiving time received from the mobile terminal, receives an information request signal from the positioning terminal, and sends the reference time which corresponds with the information request signal.

34. The mobile terminal according to claim 33, wherein the positional information includes a receiving position (P) of the mobile terminal, the time information includes a receiving time (T_R) of a signal from the base station based on the measured time measured by the mobile terminal, said signal is non-synchronous with the positioning signal from the SPS satellite and is emitted at a predetermined event of the base station, and the reference time includes a time (T_T) of the predetermined event of the base station calculated based on the position P and the time T_R received from the information providing apparatus.

35. The mobile terminal according to claim 34, wherein the information providing apparatus calculates the time T_T from a formula T_T=T_R−

|P−

Q|/c in which a position (Q) is a position of the base station, |P−

Q| is a relative distance between the mobile terminal and the position of the base station, and c is a signal propagation speed.

36. The mobile terminal according to claim 34, wherein the information providing apparatus calculates the time T_T based on sets of the position P and the time T_R received from a mobile terminal and measured at a plurality of different locations by the same mobile terminal.

37. The mobile terminal according to claim 34, wherein the information providing apparatus calculates the time T_T based on sets of the position P and the time T_R received from a plurality of mobile terminals.

38. The mobile terminal according to claims 36, wherein the information providing apparatus calculates the time T_T based on the sets of the position P and the time T_R using a least-square method.

39. The mobile terminal according to claims 37, wherein the information providing apparatus calculates the time T_T based on the sets of the position P and the time T_R using a least-square method.

40. The mobile terminal according to claim 37 further comprising a coverage cell reporting unit that sends a coverage cell report containing a coverage cell to the information providing apparatus at a power activation, a predetermined time interval or a predetermined timing, wherein the information providing apparatus generates a list of mobile terminals existing within the coverage cell based on the coverage cell report received from the plurality of the mobile terminals and requests the position P and the time T_R based on the list at either a predetermined time interval or a predetermined timing.

41. The mobile terminal according to claim 37, wherein the position P and the time T_R is sent to the information providing apparatus at either a predetermined time interval or a predetermined timing.