Estimating frequency of a GNSS enabled device based on time stamps

• US 9,651,675 B2
• Filed: 03/26/2010
• Issued: 05/16/2017
• Est. Priority Date: 02/12/2010
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Abraham, Charles, Buer, Mark, Karaoguz, Jeyhan, Lundgren, David Albert, Murray, David, Garrett, David
• Primary Examiner(s): Issing, Gregory C
• Application Number:
  US12/748,050
• Publication Number:
  US 20110199262A1
• Time in Patent Office: 2,608 Days
• Field of Search: 34235764, 34235762, 34235742
• CPC Class Codes: G01S 19/23 Testing, monitoring, correcting or calibrating of receiver elements
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/256 relating to timing, e.g. time of week, code phase, timing offset
• CPC Class Codes: G01S 19/36 relating to the receiver frond end
• CPC Class Codes: G01S 19/37 Hardware or software details of the signal processing chain

Abstract

A GNSS enabled device that is communicatively coupled to a network, receives time stamps via the network. The time stamps are generated based on reference clock signals within the network. GNSS receiver clock signal frequency may be adjusted based on the time stamps. When GNSS satellite signals and/or SRN signals are not available, the time stamps enable synchronization with GNSS satellites. Network clock signals and/or time stamps may be generated by an access point, a DSL modem, a cable modem and/or a primary reference clock within the network. A series of time stamps may be utilized for adjusting frequencies. Clock signals may be generated for adjusting frequencies based on a comparison between time stamps and oscillator or mixer output. Clock signals are generated for baseband, intermediate and/or RF frequency signal processing. GNSS satellite signals may be demodulated, correlated with a pseudonoise code sequence and/or synchronized based on the time stamps.

Claims

1. A method for communication, the method comprising:

in a GNSS enabled communication device that is communicatively coupled to a network, said GNSS enabled communication device including a transceiver, a mixer, and an oscillator;

receiving via said network using said transceiver, time stamps that are generated based on one or more reference clock signals within said network;

downconverting, by said mixer, a received GNSS satellite signal using a clock signal of said oscillator to generate a mixer output signal;

comparing a frequency of said time stamps to both a frequency of said clock signal from said oscillator and a frequency of said mixer output signal;

generating a tuning signal based on said comparison; and

adjusting a frequency of said clock signal that is generated by said oscillator based on said tuning signal, said clock signal used to demodulate said GNSS satellite signal received by said GNSS enabled communication device.

2. The method according to claim 1, comprising establishing and/or maintaining synchronization with GNSS satellite signals, based on said time stamps, when synchronization information from said GNSS satellite signals is not available and/or is not adequate for said synchronization.

3. The method according to claim 1, wherein said reference clock signals are generated in an access point, a DSL Modem, a cable modern, or a primary reference clock within said network.

4. The system according to claim 1, wherein said time stamps are received via beacon frames.

5. The method according to claim 1, comprising:

generating said clock signal based on said time stamps for baseband processing, intermediate frequency band signal processing, or RF frequency band signal processing.

6. The method according to claim 1, comprising:

correlating with a GNSS satellite signal pseudonoise code sequence based on said time stamps.

7. The method according to claim 1, comprising:

synchronizing with said GNSS satellite signal based on said time stamps.

8. A GNSS enabled communication device comprising:

a transceiver configured to communicate with a network;

an oscillator configured to generate a clock signal;

a mixer configured to downconvert a received GNSS satellite signal using said clock signal to generate a mixer output signal; and

a processor that is communicatively coupled to said transceiver, said processor configured to;

receive via said network using said transceiver, time stamps that are generated based on one or more reference dock signals within said network,

compare a frequency of said time stamps to both a frequency of said clock signal from said oscillator and to a frequency of said mixer output signal;

generate a tuning signal based on said comparison; and

adjust said frequency of said clock signal based on said tuning signal, wherein said GNSS enabled communication device is configured to demodulate said GNSS satellite signal received by said GNSS enabled communication device.

9. The GNSS enabled communication device according to claim 8, wherein said processor is configured to establish and/or maintain synchronization with GNSS satellite signals, based on said time stamps, when synchronization information from said GNSS satellite signals is not available and/or is not adequate for said synchronization.

10. The GNSS enabled communication device according to claim 8, wherein said reference clock signals are generated in an access point, a DSL Modem, a cable modem, or a primary reference clock within said network.

11. The GNSS enabled communication device according to claim 8, wherein said processor is configured to generate said clock signal based on said time stamps for baseband processing, intermediate frequency band signal processing, or RF frequency band signal processing.

12. The GNSS enabled communication device according to claim 8, wherein said processor is configured to correlate with a GNSS satellite signal pseudonoise code sequence based on said time stamps.

13. The GNSS enabled communication device according to claim 8, wherein said processor is configured to synchronize with said GNSS satellite signal based on said time stamps.

14. The GNSS enabled communication device according to claim 8, wherein the time stamps are received via beacon frames.

15. A method for communication, the method comprising:

in a GNSS enabled communication device that is communicatively coupled to a network, said GNSS enabled communication device including a mixer and an oscillator;

downconverting, by said mixer, a received GNSS satellite signal using a clock signal of said oscillator to generate a mixer output signal;

generating a tuning signal based on a comparison between a frequency of time stamps received via said network and a frequency of an output signal from said oscillator, and based on a comparison between said frequency of said time stamps and a frequency of said mixer output signal; and

adjusting a frequency of said clock signal generated by the oscillator based on said tuning signal, said clock signal used to demodulate said GNSS satellite signal received by said GNSS enabled communication device.