Positioning signal transmission apparatus

• US 7,023,382 B1
• Filed: 12/20/2004
• Issued: 04/04/2006
• Est. Priority Date: 09/17/2004
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Akano, Hiroki
• Primary Examiner(s): PHAN, DAO LINDA
• Application Number:
  US11/014,787
• Publication Number:
  US 20060071852A1
• Time in Patent Office: 470 Days
• Field of Search: 342/357.01, 342/357.06, 342/357.05, 342/386, 701/207, 701/213
• US Class Current: 342/386
• CPC Class Codes: G01S 19/11 wherein the cooperating elements are pseudolites or satellite radio beacon positioning system signal repeaters

Abstract

A reception high-frequency unit receives a GPS signal transmitted from a satellite configuring GPS. A signal generation unit generates a plurality of pseudo random noise codes that are used for the positioning operation by a positioning apparatus for implementing a positioning operation based on the GPS signal and that are in the same form as that of the GPS signal. A transmission high-frequency unit generates and transmits based on the pseudo random noise codes, a positioning signal in the same form as that of the GPS signal. A transmission control unit controls the transmission high-frequency unit in such a way that a time difference based on the GPS signal received by the reception high-frequency unit is assigned to each positioning signal and the thus-assigned positioning signal is transmitted.

Claims

1. An apparatus for transmitting a positioning signal, comprising:

a reception unit for receiving a GPS signal transmitted from a satellite configuring a global positioning system (GPS);

a signal generation unit for generating a plurality of positioning signals that are used for the positioning operation by a positioning apparatus for implementing a positioning operation based on the GPS signal and that are in a same form as that of the GPS signal;

a transmission unit for transmitting the positioning signals; and

a transmission control unit for controlling the transmission unit in such a way that assigns a time difference based on the GPS signal received by the reception unit to each positioning signal and transmits the assigned positioning signals.

2. The apparatus according to claim 1, wherein the signal generation unit generates at least three kinds of the positioning signals showing that transmission sources are different to each other.

3. The apparatus according to claim 1, wherein the signal generation unit generates the positioning signal based on a navigation message shown in the GPS signal received by the reception unit.

4. The apparatus according to claim 3, wherein the transmission control unit implements the control based on the navigation message shown in the GPS signal.

5. The apparatus according to claim 2, wherein the signal generation unit generates the positioning signal using pseudo random noise codes having different patterns.

6. The apparatus according to claim 1, wherein the transmission unit transmits the positioning signal including the navigation message shown in the GPS signal received by the reception unit.

7. The apparatus according to claim 1, wherein the reception unit is mounted in a position where the GPS signal preferably arrives in comparison with the positioning apparatus.

8. The apparatus according to claim 1, wherein the transmission unit directs a transmission direction of the positioning signal to have a directivity.

9. The apparatus according to claim 3, wherein the signal generation unit generates the positioning signal in a same form as a form of the GPS signal transmitted by the satellite that is present in the sky when the positioning signal is generated, which is shown by the navigation message.

10. The apparatus according to claim 1, wherein the transmission control unit implements the control so as to assign to each positioning signal a time difference according to a propagation time of the GPS signal from the satellite to the reception unit, thereby transmitting the assigned positioning signal.

11. The apparatus according to claim 10, wherein the transmission control unit calculates a propagation time of the GPS signal based on both a position of the satellite shown in a navigation message of the GPS signal and a position of the reception unit positioned based on the GPS signal.

12. The apparatus according to claim 10, wherein the transmission control unit calculates a propagation time of the GPS signal based on an altitude difference between a position of the reception unit and a position of a positioning apparatus for receiving a positioning signal transmitted by the transmission unit.

13. The apparatus according to claim 1, further comprising a detection unit for detecting an approach of a mobile body in a predetermined area, wherein

the transmission control unit controls the transmission unit in such a way that transmits the positioning signal according to a detection of the approach.

14. The apparatus according to claim 1, wherein:

the reception unit and the transmission unit are separately mounted; and

transmission of a signal from the reception unit to the transmission unit is implemented through a signal cable.

15. The apparatus according to claim 1, wherein:

the reception unit and the transmission unit are separately mounted; and

transmission of a signal from the reception unit.

16. The apparatus according to claim 3, wherein the signal transmission unit generates the positioning signal in a same form as a form of a GPS signal transmitted by the satellite that is present in the sky at a time of generation of the positioning signal, which is shown in the navigation message, and that cannot be used for a positioning operation in a position of the reception unit when generating the positioning signal.

17. The apparatus according to claim 1, wherein:

the transmission unit includes a transmission antenna for transmitting the positioning signal;

the reception unit includes a reception antenna for receiving the GPS signal;

the transmission antenna and the reception antenna are separately mounted; and

the transmission control unit implements the control based on a difference between a position where the transmission antenna is mounted and a position where the reception antenna is mounted.

18. A method of transmitting a positioning signal, comprising:

generating a plurality of positioning signals that are used for a positioning operation by a positioning apparatus for implementing a positioning operation based on a GPS signal transmitted from a satellite configuring a global positioning system (GPS) and that are in a same form as a form of the GPS signal; and

assigning a time difference based on the received GPS signal to each positioning signal, thereby transmitting the assigned positioning signals.

19. The positioning apparatus used in a positioning system including a positioning apparatus for implementing a positioning operation based on a GPS signal transmitted from a satellite configuring a global positioning system (GPS) and a positioning signal transmission apparatus for transmitting a positioning signal that is used for the positioning operation by the positioning apparatus and that is in a same form as a form of the GPS signal, wherein

the positioning signal transmission apparatus comprises:

a reception unit for receiving the GPS signal;

plurality of the positioning signals;

a transmission unit for transmitting the generated positioning signals by the signal generation unit; and

a transmission control unit controlling the transmission unit in such a way that assigns a time difference based on a GPS signal received by the reception unit to each positioning signal and transmits the assigned positioning signals,

the transmission unit transmits the positioning signal including a navigation message shown in the GPS signal received by the reception unit, and

the positioning apparatus comprises;

a signal reception unit for receiving a signal used for the positioning operation;

a determination unit for determining, based on the navigation message included in the signal, whether or not a signal received by the signal reception unit is transmitted by the positioning signal transmission apparatus; and

a notification unit for notifying the determination results.

20. The positioning apparatus according to claim 19, wherein

the signal generation unit generates the positioning signal in a same form as a form of the positioning signal transmitted by the satellite that is not present in the sky, which is shown in the navigation message;

and

in the case where the signal reception unit receives the positioning signal in a same form as a form of the positioning transmitted by the satellite that is not present in the sky, which is shown in the navigation message, the determination unit determines that the positioning signal is transmitted by the positioning signal transmission apparatus.

21. An apparatus for transmitting a positioning signal, comprising:

reception means for receiving a GPS signal transmitted from a satellite configuring a global positioning system (GPS);

signal generation means for generating a plurality of positioning signals that are used for the positioning operation by a positioning apparatus for implementing a positioning operation based on the GPS signal and that are in a same form as that of the GPS signal;

transmission means for transmitting the positioning signals; and

transmission control means for controlling the transmission means in such a way that assigns a time difference based on the GPS signal received by the reception means to each positioning signal and transmits the assigned positioning signals.

22. The positioning apparatus used in a positioning system including a positioning apparatus for implementing a positioning operation based on a GPS signal transmitted from a satellite configuring a global positioning system (GPS) and a positioning signal transmission apparatus for transmitting a positioning signal that is used for the positioning operation by the positioning apparatus and that is in a same form as a form of the GPS signal, wherein

the positioning signal transmission apparatus comprises:

reception means for receiving the GPS signal;

signal generation means for generating a plurality of positioning signals;

transmission means for transmitting the generated positioning signals by the signal generation means; and

transmission control means for controlling the transmission means in such a way that assigns a time difference based on a GPS signal received by the reception means to each positioning signal and transmits the assigned positioning signals,

the transmission means transmits the positioning signal including a navigation message shown in the GPS signal received by the reception means, and

the positioning apparatus comprises;

signal reception means for receiving a signal used for the positioning operation;

determination means for determining, based on the navigation message included in the signal, whether or not a signal received by the signal reception means is transmitted by the positioning signal transmission apparatus; and

notification means for notifying the determination results.

23. An apparatus for transmitting a positioning signal, wherein the apparatus includes a code/signal processor to process code and signals, the code/signal processor comprising:

a signal generator to generate a plurality of positioning signals used to implement a positioning operation based on a received global positioning system (GPS) signal transmitted from a GPS satellite and, wherein the positioning signals are in a same form as a form of the GPS signal; and

an assignment generator to assign a time difference based on the received GPS signal to each positioning signal to provide assigned positioning signals.