Global positioning system (GPS) and GPS receiver

• US 6,463,386 B2
• Filed: 12/05/2001
• Issued: 10/08/2002
• Est. Priority Date: 12/20/2000
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Kimura, Tsunekazu, Mieno, Masayuki
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Hernandez, Olga
• Application Number:
  US10/006,070
• Publication Number:
  US 20020077751A1
• Time in Patent Office: 307 Days
• Field of Search: 701/213, 731/78.R, 342/357.03, 342/357.06, 342/357.09, 342/357.1, 342/357.12, 342/357.13, 342/358
• US Class Current: 701/213
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/24 Acquisition or tracking or demodulation of signals transmitted by the system synchronisation aspects of direct sequence spread spectrum modulation H04B1/7073
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/29 carrier including Doppler, related G01S19/246 takes precedence
• CPC Class Codes: G01S 19/30 code related G01S19/246 takes precedence

Abstract

To enable positional information to be provided even if a signal intensity of a received GPS signal is low by compensating a phase inversion of a navigation message and performing a phase integration over a long period. A base station 20 continuously receives the GPS signal 11 and extracts therefrom information for supporting reception and positioning computation in a GPS receiver 30 and retains the information. The base station 20 transmits the support information to the GPS receiver 30 via a communication line 40 when the GPS receiver needs the information. The base station 20 supports reception time synchronization in the GPS receiver 30. The GPS receiver 30 receives the GPS signal 11, generates an intermediate frequency signal through down-conversion, and then stores an A/D conversion data in a memory unit. In the GPS receiver 30, the GPS signal data stored in the memory unit 33 is subjected to integration with phase of the GPS signals aligned based on the support information (satellite navigation message and phase inversion information) supplied from the base station 20, and then positioning computation is performed using the integral GPS data.

Claims

1. A global positioning system (GPS) receiver, comprising:

a high frequency unit for frequency-converting a received GPS signal to output an intermediate frequency signal;

an A/D converter unit for A/D converting said intermediate frequency signal to output an intermediate frequency signal sample data;

a memory unit for storing said intermediate frequency signal sample data for a predetermined period of time, the data being associated with a time series;

a communication unit for communicating with a base station;

an integration unit for subjecting said intermediate frequency signal sample data stored in said memory unit to a phase correction based on phase inversion information of a navigation message supplied from said base station, and then performing a phase integration on all of said intermediate frequency signal sample data for the predetermined period of time to output a result of the phase integration; and

a GPS computation unit for computing positional information based on said result of the phase integration.

2. A global positioning system (GPS), comprising:

a GPS receiver including, a high frequency unit for frequency-converting a received GPS signal to output an intermediate frequency signal, an A/D converter unit for A/D converting said intermediate frequency signal to output an intermediate frequency signal sample data, a memory unit for storing said intermediate frequency signal sample data for a predetermined period of time, the data being associated with a time series, a communication unit for communicating with a base station, an integration unit for subjecting said intermediate frequency signal sample data stored in said memory unit to a phase correction based on phase inversion information of a navigation message supplied from said base station, and then performing a phase integration on all of said intermediate frequency signal sample data for the predetermined period of time to output a result of the phase integration, and a GPS computation unit for computing positional information based on said result of the phase integration; and

the base station for providing the phase inversion information of the navigation message and information for supporting a positioning computation to the GPS receiver.

3. The global positioning system according to claim 2,

wherein said GPS receiver automatically determines said integration process time for the least necessary length in accordance with GPS signal conditions.

4. The global positioning system according to claim 2,

wherein said GPS receiver operates said integration process only when it is necessary in accordance with GPS signal conditions.

5. The global positioning system according to claim 2,

wherein said GPS integration process is provoked only when it is considered to be the best cost-effective among other hi-sensitive GPS algorithms or generic GPS algorithm.

6. The global positioning system according to claim 2,

wherein said GPS receiver and said base station are connected to each other via the Internet.

7. The global positioning system according to claim 2,

wherein said GPS receiver and said base station are connected to each other via a mobile phone network.

8. The global positioning system according to claim 2,

wherein said GPS receiver and said base station are connected to each other via the Internet and a mobile phone network.

9. The global positioning system according to claim 2,

wherein a server-client system is adopted in which said GPS receiver is a client and said base station is a server.

10. The global positioning system according to claim 6,

wherein a server-client system is adopted in which said GPS receiver is a client and said base station is a server.

11. The global positioning system according to claim 7,

wherein a server-client system is adopted in which said GPS receiver is a client and said base station is a server.

12. The global positioning system according to claim 8,

wherein a server-client system is adopted in which said GPS receiver is a client and said base station is a server.

13. A computer program product stored in a computer-readable recording medium that is used in a GPS receiver,

wherein the computer program product makes a computer execute the process of:

frequency-converting a received GPS signal to output an intermediate frequency signal;

A/D converting said intermediate frequency signal to output intermediate frequency signal sample data;

storing said intermediate frequency signal sample data for a predetermined period of time in a memory unit, the data being associated with a time series;

communicating with a base station and subjecting said intermediate frequency signal sample data stored in said memory unit to a phase correction based on phase inversion information of a navigation message supplied from said base station;

performing a phase integration on all of said intermediate frequency signal sample data for the predetermined period of time to output a result of the phase integration; and

computing positional information based on said result of the phase integration.