System and method for position detection of a terminal in a network

• US 20050078033A1
• Filed: 06/15/2004
• Published: 04/14/2005
• Est. Priority Date: 10/14/2003
• Status: Active Grant

• Current Assignee: Maxell, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ogino, Atsushi, Yamasaki, Ryota, Uta, Takaki, Tamaki, Tsuyoshi
• Granted Patent: US 7,138,946 B2
• Time in Patent Office: Days
• US Class Current: 342/463
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: G01S 5/0268 by deriving positions from different combinations of signals or of estimated positions in a single positioning system
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308

Abstract

In a position detection system for detecting a position of a terminal apparatus of a radio communications system, a position detection time is shortened using a position detection method for determining signal times-of-arrival between the terminal apparatus and base stations neighboring the terminal apparatus. According to the present invention, means for generating a database in which received power information about signals transferred between the terminal apparatus and the base stations neighboring the terminal apparatus corresponds to position information about the terminal apparatus, and for determining the position information by searching received power information obtained in the position detection from the database, and means for determining the position by use of signal times-of-arrival are executed in parallel. Then, the use of a result of the means which has detected the position earlier than another means shortens the position detection time.

Claims

1. A method for determining a position of a terminal in a system having a terminal apparatus, a plurality of base stations in communication with the terminal apparatus, and a server apparatus connected to the plurality of base stations via a network, the method comprising:

detecting via the server apparatus a position of the terminal apparatus through at least either a first position detection process or a second position detection process;

performing a first position detection process, including receiving at others of the plurality of base stations signals transferred between one of the plurality of base stations and the terminal apparatus, collecting at the server apparatus information about reception timings of the signals received at each of the others of the plurality base stations, and calculating a position of the terminal apparatus using a plurality of the reception timings and position information about the others of the plurality of base stations;

performing a second position detection process, including collecting at the server apparatus measurement information about received powers of signals transferred between the terminal apparatus and the others of the plurality of base stations, and searching a received power measurement information database previously stored in the server apparatus using a plurality of the measurement information about the received powers, and determining a position of the terminal apparatus based on the searching;

storing via the received power measurement information database position information and received power measurement information from the others of the plurality of base stations which correspond to positions shown in the position information, the position information corresponding to the received power measurement information, the received power measurement information being the received powers or reception timings of the received signals; and

determining via the server apparatus whether to execute the second position detection process according to information stored in the received power measurement information database.

2. The method of claim 1, further comprising:

executing via the server apparatus the first and second position detection processes in parallel;

outputting via the server apparatus position information of the terminal apparatus; and

determining the position information according to a result of the position detection process which has completed earlier than another.

3. The method of claim 1, further comprising:

determining a position of the terminal apparatus by way of the first position detection process;

collecting via the server apparatus measurement information about the received signal powers when the terminal apparatus is at the determined position; and

storing via the received power measurement information database the determined position and the received power measurement information about the received signal powers, the determined position corresponding to the measurement information.

4. The method of claim 1, further comprising at the server apparatus:

determining a position range by executing the second position detection process;

evaluating position detection errors of a plurality of positions within the position range; and

determining a position having a smallest error as the position of the terminal apparatus.

5. The method of claim 1, wherein the received power information is information about received powers of signals transmitted from a plurality of the base stations to the terminal apparatus, the received powers being measured in the terminal apparatus.

6. The position detection method according to claim 1, wherein the received power information is information about received powers of signals transmitted from the terminal apparatus to a plurality of the base stations, the received powers being measured in a plurality of the base stations.

7. The method of claim 1, further comprising at the server apparatus:

determining whether to execute the first or second position detection process; and

requesting information required for the determined position detection process from a plurality of the base stations.

8. A system for detecting a position of a terminal, the system comprising:

a terminal apparatus;

a plurality of base stations in radio communication with the terminal apparatus;

a server apparatus connected to a plurality of the base stations via a network,

wherein the server apparatus includes a position detection process portion and a storage apparatus having a received power measurement information database,

wherein the position detection process portion is configured to detect a position of the terminal apparatus through at least one of a first or second position detection process,

wherein the first position detection process includes receiving at others of the plurality of base stations signals transferred between one of the plurality of base stations and the terminal apparatus, collecting at the server apparatus information about reception timings of the signals received at each of the others of the plurality base stations, and calculating a position of the terminal apparatus using a plurality of the reception timings and position information about the others of the plurality of base stations,

wherein the second detection process includes collecting at the server apparatus measurement information about received powers of signals transferred between the terminal apparatus and the others of the plurality of base stations, and searching a received power measurement information database previously stored in the server apparatus using a plurality of the measurement information about the received powers, and determining a position of the terminal apparatus based on the searching,

wherein the received power measurement information database is configured to store position information and received power measurement information from the others of the plurality of base stations which correspond to positions shown in the position information, the position information corresponding to the received power measurement information, the received power measurement information being the received powers or reception timings of the received signals position information and received power measurement information from the others of the plurality of base stations which correspond to positions shown in the position information, the position information corresponding to the received power measurement information, the received power measurement information being the received powers or reception timings of the received signals, and

wherein the position detection process portion includes determining whether to execute the second position detection process according to the information stored in the received power measurement information database.

9. The system of claim 8, wherein the position detection process portion of the server apparatus is configured to execute the first and second position detection processes in substantially parallel and to output position information about the terminal apparatus, the position information being determined according to a result of the position detection process which has completed earlier than another.

10. The system of claim 8, wherein the first position detection process is configured to determine a position of the terminal apparatus, wherein the server apparatus is configured to collect measurement information about the received signal powers when the terminal apparatus is at the determined position, and wherein the received power measurement information database is configured to store the determined position the measurement information about the received signal powers, the determined position corresponding to the measurement information.

11. The system of claim 8, wherein the position detection process portion is configured to execute the second position detection process to determine a position range, to evaluate a position detection error of a plurality of positions within the position range, and to determine a position having the smallest error as a position of the terminal apparatus.

12. The system of claim 8, wherein the measurement information about received powers is information about received powers of received signals transmitted from the terminal apparatus to a plurality of the base stations, the received powers being measured in a plurality of the base stations.

13. The system of claim 8, wherein the received power information is information about received powers of received signals transmitted from the terminal apparatus to a plurality of the base stations, the received powers being measured in a plurality of the base stations.

14. A server apparatus of a terminal position detection system including a terminal apparatus, a plurality of base stations in radio communication with the terminal, and a server apparatus connected to a plurality of the base stations, the server apparatus comprising:

a position detection process portion configured to detect a position of the terminal apparatus through at least a first or second position detection process; and

a storage apparatus including a measurement information database,

wherein the server apparatus includes a position detection process portion and a storage apparatus having a received power measurement information database,

wherein the position detection process portion is configured to detect a position of the terminal apparatus through at least one of a first or second position detection process,

wherein the first position detection process includes receiving at others of the plurality of base stations signals transferred between one of the plurality of base stations and the terminal apparatus, collecting at the server apparatus information about reception timings of the signals received at each of the others of the plurality base stations, and calculating a position of the terminal apparatus using a plurality of the reception timings and position information about the others of the plurality of base stations,

wherein the second detection process includes collecting at the server apparatus measurement information about received powers of signals transferred between the terminal apparatus and the others of the plurality of base stations, and searching a received power measurement information database previously stored in the server apparatus using a plurality of the measurement information about the received powers, and determining a position of the terminal apparatus based on the searching, wherein the received power measurement information database is configured to store position information and received power measurement information from the others of the plurality of base stations which correspond to positions shown in the position information, the position information corresponding to the received power measurement information, the received power measurement information being the received powers or reception timings of the received signals position information and received power measurement information from the others of the plurality of base stations which correspond to positions shown in the position information, the position information corresponding to the received power measurement information, the received power measurement information being the received powers or reception timings of the received signals, and

wherein the position detection process portion includes determining whether to execute the second position detection process according to the information stored in the received power measurement information database.

15. The server apparatus of claim 14, wherein the position detection process portion is configured to execute the first and second position detection processes in parallel, and to output position information about the terminal apparatus, the position information being determined according to a result of the position detection process which has completed earlier than another.

16. The server apparatus of claim 14, wherein the first position detection process is configured to determine a position of the terminal apparatus, wherein the server apparatus is configured to collect measurement information about the received signal powers when the terminal apparatus is at the determined position, and wherein the received power measurement information database is configured to store the determined position the measurement information about the received signal powers, the determined position corresponding to the measurement information.

17. The server apparatus according to claim 14, wherein the position detection process portion is configured to execute the second position detection process to determine a position range, to evaluate a position detection error of a plurality of positions within the position range, and to determine a position having the smallest error as a position of the terminal apparatus.

18. The server apparatus according to claim 14, wherein the received power information is information about received powers of received signals transmitted from a plurality of the base stations to the terminal apparatus, the received powers being measured in the terminal apparatus.

19. The server apparatus according to claim 14, wherein the measurement information about received powers is information about received powers of received signals transmitted from the terminal apparatus to a plurality of the base stations, the received powers being measured in a plurality of the base stations.