POSITIONING APPARATUS AND POSITIONING APPARATUS CONTROL METHOD

• US 20090079626A1
• Filed: 05/15/2008
• Published: 03/26/2009
• Est. Priority Date: 05/21/2007
• Status: Active Grant

• Current Assignee: Panasonic Semiconductor Solutions Co., Ltd. (Winbond Electronics Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: KOBAYASHI, Yosuke
• Granted Patent: US 7,903,026 B2
• Time in Patent Office: Days
• US Class Current: 342/357.720
• CPC Class Codes: G01S 19/22 Multipath-related issues
• CPC Class Codes: G01S 19/32 Multimode operation in a single same satellite system, e.g. GPS L1/L2
• CPC Class Codes: G01S 19/34 Power consumption

Abstract

The positioning apparatus and position apparatus control method are able to efficiently receive useful signals without special circuitry. Positioning apparatus 100 has first signal processing section 121 that carries out demodulation processing on the first signal transmitted from a satellite and second signal processing section 122 that carries out demodulation processing on the second signal of a different frequency band and spreading scheme from the first signal, and controlling section 104 controls the operation for the signal of the lower electric field intensity based on operations for the signal of the higher electric field intensity between first signal processing section 121 and second signal processing section 122, and carries out control to preferentially operate the channel for the signal of the higher electric field intensity between first signal processing section 121 and second signal processing section 122 and to preferentially stop the operation of the channels for the signal of the lower electric field intensity.

Claims

1. A positioning apparatus with a plurality of channels for scanning or tracking satellite signals, the apparatus comprising:

a first signal processing section that carries out demodulation processing on a first signal transmitted from a satellite;

a second signal processing section that carries out demodulation processing on a second signal of a different frequency band or spreading scheme from the first signal;

a positioning section that calculates a distance from the positioning apparatus to the satellite based on results of the demodulation processings on the first signal and the second signal and carries out positioning arithmetic operation;

an electric field intensity comparing section that measures an electric field intensity difference between the first signal and the second signal transmitted from the same satellite, based on the results of the demodulation processings in the first signal processing section and the second signal processing section;

an electric field intensity storing section that stores the electric field intensity difference; and

a controlling section that controls operations of channels in the first signal processing section and channels in the second signal processing section, based on electric field intensity information in the electric field intensity storing section,

wherein, between the first signal processing section and the second signal processing section, the controlling section controls an operation for a signal of a lower electric field intensity based on operations for a signal for a higher electric field intensity.

2. The positioning apparatus according to claim 1, wherein, between the first signal processing section and the second signal processing section, the controlling section preferentially operates the channels for the higher electric field intensity and preferentially stops the channels for the lower electric field intensity.

3. The positioning apparatus according to claim 1, wherein, between the first signal processing section and the second signal processing section, if received power for a signal of the higher electric field intensity is equal to or more than a predetermined value, the controlling section stops the operation of the channels for the signal of the lower electric field intensity.

4. The positioning apparatus according to claim 1, wherein, between the first signal processing section and the second signal processing section, if received power for a signal of the higher electric field intensity is more than a predetermined value, the controlling section operates the channels for the signal of the lower electric field intensity.

5. The positioning apparatus according to claim 3, wherein stopping of the operation comprises stopping supplying clock or turning on electricity.

6. The positioning apparatus according to claim 1, wherein the controlling section demodulates the first signal and the second signal transmitted from the same satellite and, if one signal is demodulated and the electric field intensity is measured, changes an integration period for the other signal that is not yet demodulated.

7. The positioning apparatus according to claim 1, wherein, if one of the first signal and the second signal transmitted from the same satellite cannot be demodulated even after a certain time passes, the controlling section decides that a jamming signal is captured in the demodulated signal and resets an operation.

8. The positioning apparatus according to claim 1, wherein the controlling section decides whether multipath signals are received, based on the electric field intensity difference between the first signal and the second signal transmitted from the same satellite.

9. The positioning apparatus according to claim 1, wherein, if the electric field intensity difference between the first signal and the second signal is different from a value of the electric field intensity storing section, the controlling section carries out control such that the satellite is not used for positioning arithmetic operation.

10. The positioning apparatus according to claim 1, wherein, if the electric field intensity difference between the first signal and the second signal transmitted from the same satellite is equal to or more than a predetermined value or greater, the electric field intensity storing section stores the electric field intensity difference.

11. The positioning apparatus according to claim 1, further comprising a signal attenuation amount calculating section that calculates amounts of signal attenuation in signal transmission of the first signal and the second signal transmitted from the same satellite, using the distance between the positioning apparatus and the satellite calculated by the positioning section,

wherein the electric field storing section adds the amounts of signal attenuation to the electric field intensity difference obtained by the electric field intensity comparing section and stores a result.

12. The positioning apparatus according to claim 1, further comprising an electric field intensity setting section that sets the electric field intensity difference,

wherein the electric field intensity storing section stores the electric field intensity difference set from remote apparatus.

13. The positioning apparatus according to claim 1, wherein the satellite signals include at least two of an L1 band signal, an L2 band signal and an L5 band signal transmitted by a global positioning system satellite.

14. A control method of a positioning apparatus with a plurality of channels for scanning or tracking satellite signals, the method comprising;

a first signal processing step of carrying out demodulation processing on a first signal transmitted from a satellite;

a second signal processing step of carrying out demodulation processing on a second signal of a different frequency band or spreading scheme from the first signal;

a positioning step of calculating a distance from the positioning apparatus to the satellite based on results of the demodulation processings on the first signal and the second signal and carrying out positioning arithmetic operation;

an electric field intensity comparing step of measuring an electric field intensity difference between the first signal and the second signal transmitted from the same satellite, based on the results of the demodulation processings in the first signal processing step and the second signal processing step;

an electric field intensity storing step of storing the electric field intensity difference; and

a controlling step of controlling operations of channels in the first signal processing step and channels in the second signal processing step, based on information of the stored electric field intensity difference.

15. The control method of the positioning apparatus according to claim 14, wherein, between in the first signal processing step and in the second signal processing step, operations for a signal of a lower electric field intensity is controlled based on operations for a signal of a higher electric field intensity.

16. The control method of the positioning apparatus according to claim 14, wherein, between in the first signal processing step and in the second signal processing step, channels for a signal of a higher electric field intensity are preferentially operated and channels for a signal of a lower electric field intensity are preferentially stopped.