SIGNAL ACQUIRING METHOD OF GPS RECEIVER AND DIGITAL CAMERA THEREOF

• US 20090167602A1
• Filed: 06/20/2008
• Published: 07/02/2009
• Est. Priority Date: 12/26/2007
• Status: Active Grant

• Current Assignee: Altek Company Limited
• Original Assignee: Altek Corporation
• Inventors: Huang, Chao-Hui
• Granted Patent: US 7,928,904 B2
• Time in Patent Office: Days
• US Class Current: 342/357.310
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 19/254 relating to Doppler shift of satellite signals
• CPC Class Codes: G01S 19/30 code related G01S19/246 takes precedence
• CPC Class Codes: G01S 19/37 Hardware or software details of the signal processing chain
• CPC Class Codes: G03B 29/00 Combinations of cameras, projectors or photographic printing apparatus with non-photographic non-optical apparatus, e.g. clocks or weapons; Cameras having the shape of other objects combinations with flash apparatus G03B15/03

Abstract

A signal acquiring method of a GPS receiver and a digital camera thereof, suitable for accelerating a signal acquiring speed of the GPS receiver, are described. The signal acquiring method includes the following steps receiving a plurality of satellite signals; performing a discrete cosine transform (DCT) demodulation procedure, so as to parse a receiving time base of the satellite signals; next, transforming the satellite signals into a code information and a navigation frequency according to the receiving time base of the satellite signals; then, performing a correlation correction procedure to acquire a navigation information from the satellite signals according to the code information and the navigation frequency; which thus accelerates the processing speed on the signal acquiring flow through calculation characteristics of the DCT.

Claims

1. A signal acquiring method of a global positioning system (GPS) receiver, for accelerating a signal acquiring speed of the GPS receiver, comprising:

receiving a plurality of satellite signals;

performing a discrete cosine transform (DCT) demodulation procedure, to parse a receiving time base of the satellite signals;

transforming the satellite signals into a code information and a navigation frequency, according to the receiving time base of the satellite signals; and

performing a correlation correction procedure for acquiring a navigation information from the satellite signals, according to the code information and the navigation frequency.

2. The signal acquiring method of a GPS receiver as claimed in claim 1, wherein the step of receiving the satellite signals further comprises:

performing a down converting means, for converting the satellite signals down to a preset frequency; and

performing an analog-to-digital conversion, for converting the received satellite signals into digital signals.

3. The signal acquiring method of a GPS receiver as claimed in claim 1, after acquiring the navigation information, further comprising:

performing a navigation calculation, to calculate a distance, a Doppler shift, and a relative speed between the GPS receiver and the satellite according to the satellite signals.

4. The signal acquiring method of a GPS receiver as claimed in claim 1, wherein the DCT is a fast DCT, and equations thereof are listed as follows:

5. A digital camera provided with a signal acquiring process of a GPS, for accelerating a signal acquiring speed of the GPS receiver, comprising:

a photographing module, for receiving a plurality of image data;

a DCT module, electrically connected to the photographing module, and used to perform an image compression means on the image data received by the photographing module, thereby generating a corresponding compressed image;

a GPS receiver, for receiving a plurality of satellite signals; and

an arithmetic unit, electrically connected to the DCT module and the GPS receiver respectively, and used to perform a signal modulation means on the satellite signals, thereby parsing a receiving time base of the satellite signals and acquiring a navigation information from the satellite signals.

6. The digital camera provided with a signal acquiring process of a GPS as claimed in claim 5, wherein the GPS receiver further comprises:

an antenna, for receiving the satellite signals;

a radio frequency (RF) front end, electrically connected to the antenna, and used to perform filtering and signal amplifying on the satellite signals;

a frequency synthesizer, electrically connected to the RF front end;

a reference oscillator, electrically connected to the frequency synthesizer, and provided for the frequency synthesizer to generate a carrier wave to the RF front end, so as to perform a wave mixing process; and

an analog-to-digital converter, electrically connected to the RF front end, and used to convert analog signals into digital signals.