Method for determining A change in A communication signal and using this information to improve SPS signal reception and processing

• US 8,369,873 B2
• Filed: 08/09/2007
• Issued: 02/05/2013
• Est. Priority Date: 07/20/1999
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc., Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm, Inc.
• Inventors: Krasner, Norman F.
• Primary Examiner(s): Nguyen, Duc
• Assistant Examiner(s): CHOW, CHARLES CHIANG
• Application Number:
  US11/836,643
• Publication Number:
  US 20080158051A1
• Time in Patent Office: 2,007 Days
• Field of Search: 455/456.3, 455/441, 455/424, 455/425, 455/456.5, 455/456.6, 455/561, 455/550.1, 455/575.1, 455/337.01, 455/506, 455/226.2, 455/443, 455/436, 455/437, 455/404.2, 455/433, 455/412.2, 455/414.2, 455/440, 455/456.1, 455/407, 455/67.11, 455/408, 455/98, 455/100, 455/164.1, 455/192.1, 455/173.1, 342/352, 342/357.02, 342/358, 342/357.09, 342/375.15, 342/357.12, 342/357.1, 342/357.06, 364/449, 701/207, 701/214, 701/213, 701/209, 701/13, 701/200, 375/150, 375/343, 370/252, 370/316
• US Class Current: 455/456.3
• CPC Class Codes: G01P 3/50 for measuring linear speed G01P3/56 takes precedence
• CPC Class Codes: G01P 3/64 Devices characterised by the determination of the time taken to traverse a fixed distance
• CPC Class Codes: G01S 11/02 using radio waves G01S19/00 takes precedence
• CPC Class Codes: G01S 11/06 using intensity measurements
• CPC Class Codes: G01S 19/254 relating to Doppler shift of satellite signals
• CPC Class Codes: G01S 19/26 involving a sensor measurement for aiding acquisition or tracking
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/221 using past power control commands
• CPC Class Codes: H04W 64/006 with additional information processing, e.g. for direction or speed determination

Abstract

Methods and apparatuses for determining a position of a mobile satellite positioning system (SPS) receiver which is coupled to a communication receiver or transceiver. In one exemplary method, a change in a communication signal received by the communication receiver is determined. A parameter, based on the change, is determined, and SPS signals from SPS satellites are processed according to the parameter. According to further details of this method, the change involves the fluctuation of the level of the communication signal and the parameter is a motion information which specifies a frequency range for searching for SPS signals in the process of acquiring the SPS signals from SPS satellites. In an alternative embodiment the change in the communication signal is a change in the transmitted signal in response to power control commands. Apparatuses, such as a mobile communication system which includes an SPS receiver and a communication receiver, are also described.

Claims

1. A mobile communication apparatus for acquiring a satellite positioning system signal, the apparatus comprising:

means for receiving a cellular communication signal at the mobile communication apparatus;

a measurement unit that determines a change in the received cellular communication signal resulting from motion of the mobile communication apparatus and approximates motion information of the mobile communication apparatus in accordance with the determined change;

means for determining a Doppler search window about a predetermined signal frequency of the satellite positioning system signal based on the approximate motion information; and

means for acquiring the satellite positioning system signal at the mobile communication apparatus using said Doppler search window.

2. The apparatus of claim 1 wherein the change in the received cellular communication signal resulting from motion of the mobile communication apparatus is the fluctuation of the received signal due to Rayleigh fading.

3. The apparatus of claim 1 wherein the change in the received cellular communication signal resulting from motion of the mobile communication apparatus is represented by power control commands that control transmit power of the mobile communication apparatus.

4. The apparatus of claim 1 wherein the change in the received cellular communication signal resulting from motion of the mobile communication apparatus is represented by the transmit power of the mobile communication apparatus.

5. The apparatus of claim 1 wherein the measurement unit comprises means for accessing a lookup table and converting the change in the received cellular communication signal to approximate motion information based on entries in the lookup table.

6. The apparatus of claim 1 wherein the approximate motion information is based on a known mathematical relationship between the approximate motion information and the change in the received cellular communication signal and a wavelength of the received cellular communication signal.

7. The apparatus of claim 1 wherein the measurement unit comprises:

means for accessing a graph containing a representation between the change in the received cellular communication signal and approximate motion information; and

means for interpolating the approximate motion information from a point on the graph that corresponds to the change in the received cellular communication signal.

8. The apparatus of claim 1, wherein the means for determining a Doppler search window increases a frequency range for the Doppler search window in response to the approximate motion information indicating a faster speed of the mobile communication apparatus.

9. The apparatus of claim 1, wherein the means for determining a Doppler search window determines the Doppler search window based upon Doppler associated with motion of a satellite transmitting the satellite positioning system signal and based upon Doppler associated with the approximate motion information.

10. A non-transitory computer-readable medium of a mobile communication apparatus including instructions stored thereon configured to cause a computer to acquire a satellite positioning system signal, the instructions comprising:

instructions to determine a change in a received cellular communication signal resulting from motion of the mobile communication apparatus and determine approximate motion information in accordance with the determined change;

instructions to determine a Doppler search window about a predetermined signal frequency of the satellite positioning system signal based on the approximate motion information; and

instructions to acquire the satellite positioning system signal using said Doppler search window.

11. The non-transitory computer-readable medium of claim 10 wherein the change in the received cellular communication signal resulting from motion of the mobile communication apparatus is the fluctuation of the received signal due to Rayleigh fading.

12. The non-transitory computer-readable medium of claim 10 wherein the change in the received cellular communication signal resulting from motion of the mobile communication apparatus is represented by power control commands that control transmit power of the mobile communication apparatus.

13. The non-transitory computer-readable medium of claim 10 wherein the change in the received cellular communication signal resulting from motion of the mobile communication apparatus is represented by transmit power of the mobile communication apparatus.

14. The non-transitory computer-readable medium of claim 10 wherein the instructions to determine a change in a received cellular communication signal resulting from motion of the mobile communication apparatus and determine approximate motion information in accordance with the determined change comprise instructions to access a lookup table and convert the change in the received cellular communication to approximate motion information based on entries in the lookup table.

15. The non-transitory computer-readable medium of claim 10 wherein the approximate motion information is based on a known mathematical relationship between the approximate motion information and the change in the received cellular communication signal and a wavelength of the received cellular communication signal.

16. The non-transitory computer-readable medium of claim 10 wherein the instructions to determine a change in a received cellular communication signal resulting from motion of the mobile communication apparatus and determine approximate motion information in accordance with the determined change comprise:

instructions to access a graph containing a representation between the change in the received cellular communication signal and approximate motion information; and

instructions to interpolate the approximate motion information from a point on the graph that corresponds to the change in the received cellular communication signal.

17. The non-transitory computer-readable medium of claim 10 wherein the instructions to determine a Doppler search window comprise instructions to increase a frequency range for the Doppler search window in response to the approximate motion information indicating a faster speed of the mobile communication apparatus.

18. The non-transitory computer-readable medium of claim 10 wherein the instructions to determine a Doppler search window comprise instructions to determine the Doppler search window based upon Doppler associated with motion of a satellite transmitting the satellite positioning system signal and based upon Doppler associated with the approximate motion information.

19. A method for acquiring a satellite positioning system signal in a mobile communication apparatus, the method comprising:

receiving a cellular communication signal at the mobile communication apparatus;

determining a change in the received cellular communication signal resulting from motion of the mobile communication apparatus and approximating motion information of the mobile communication apparatus in accordance with the determined change;

determining a Doppler search window about a predetermined signal frequency of the satellite positioning system signal based on the approximate motion information;

acquiring the satellite positioning system signal at the mobile communication apparatus using said Doppler search window.

20. A mobile communication apparatus for acquiring a satellite positioning system signal, the apparatus comprising:

a receiver configured to receive a cellular communication signal;

a measurement unit communicatively coupled to the receiver and configured to determine a change in the received cellular communication signal resulting from motion of the mobile communication apparatus and approximate motion information of the mobile communication apparatus in accordance with the determined change; and

a processor communicatively coupled to the measurement unit and configured to;

determine a Doppler search window about a predetermined signal frequency of the satellite positioning system signal based on the approximate motion information; and

acquire the satellite positioning system signal using said Doppler search window.