Method and apparatus for mitigating interference in a satellite signal receiver

• US 20040247058A1
• Filed: 06/05/2003
• Published: 12/09/2004
• Est. Priority Date: 06/05/2003
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Global Locate Incorporated (Broadcom, Inc.)
• Inventors: Abraham, Charles
• Granted Patent: US 7,724,846 B2
• Time in Patent Office: Days
• US Class Current: 375/346
• CPC Class Codes: G01S 19/21 Interference related issues ; Issues related to cross-correlation, spoofing or other methods of denial of service
• CPC Class Codes: H04B 1/3805 with built-in auxiliary receivers
• CPC Class Codes: H04B 2201/70709 with discontinuous detection
• CPC Class Codes: H04B 2201/709709 Methods of preventing interference
• CPC Class Codes: H04B 7/1851 Systems using a satellite or space-based relay H04B7/18508, H04B7/18521 take precedence; providing specific services H04B7/18523 - H04B7/18576

Abstract

A method and apparatus for mitigating interference in a satellite signal receiver is described. The satellite signal receiver receives satellite signals from a plurality of satellites. In one example, data transmission of a wireless transceiver operating in proximity to the satellite signal receiver is monitored. A control signal is transmitted to the satellite signal receiver upon occurrence of data transmission from the wireless transceiver. Signal integration within the satellite signal receiver is then gated is response to the control signal. In another example, one or more values of satellite signal samples are selected from a plurality of possible values. A percentage of satellite signal samples having the one or more selected values is monitored over a predefined period. Signal integration within the satellite signal receiver is gated in response to the percentage exceeding a predefined threshold. In yet another example, a gain setting of an automatic gain control circuit within the satellite signal receiver is adjusted in response to detection of interference.

Claims

1. A method of mitigating interference in a satellite signal receiver receiving satellite signals from a plurality of satellites, the method comprising:

monitoring data transmission of a wireless transceiver operating in proximity to the satellite signal receiver;

transmitting a control signal to the satellite signal receiver upon occurrence of data transmission from the wireless transceiver; and

gating signal integration within the satellite signal receiver in response to the control signal.

2. The method of claim 1, wherein the gating comprises:

disabling the signal integration in response to the control signal having a first state; and

enabling the signal integration in response to the control signal having a second state.

3. The method of claim 1, wherein the control signal includes information indicative of signal power associated with the data transmission, and the gating comprises:

disabling the signal integration in response to an indication by the control signal of the signal power exceeding a predefined threshold; and

enabling the signal integration in response to an indication by the control signal of the signal power being below the predefined threshold.

4. The method of claim 1, wherein signal integration comprises accumulation of signal correlations over a predefined period.

5. The method of claim 4, wherein the signal correlations comprises in-phase signal correlations and quadrature phase signal correlations.

6. The method of claim 4, wherein signal integration further comprises accumulation of values indicative of the magnitude or power of the signal correlations over a predefined period.

7. The method of claim 1, further comprising:

substantially holding a gain setting of an automatic gain control block within the satellite signal receiver in response to the control signal.

8. The method of claim 1, further comprising:

driving a gain setting of an automatic gain control block within the satellite signal receiver to a pre-defined value in response to the control signal.

9. A method of mitigating interference in a satellite signal receiver receiving satellite signals from a plurality of satellites, the method comprising:

selecting one or more values of satellite signal samples from a plurality of possible values;

monitoring a percentage of satellite signal samples having the one or more selected values over a predefined period; and

gating signal integration within the satellite signal receiver in response to the percentage exceeding a predefined threshold.

10. The method of claim 9, wherein the gating comprises:

determining a deviation of the percentage from an expected percentage;

disabling the signal integration in response to the deviation exceeding a predefined threshold; and

enabling the signal integration in response to the deviation being below the predefined threshold.

11. The method of claim 10, wherein the satellite signal samples comprise a sign bit and a magnitude bit.

12. The method of claim 11, wherein the one or more values comprise values of the satellite signal samples having a logically high magnitude bit.

13. The method of claim 11, wherein the expected percentage is approximately 34% and the predefined threshold is approximately 60%.

14. The method of claim 9, further comprising:

monitoring data transmission of a wireless transceiver operating in proximity to the satellite signal receiver; and

transmitting a control signal to the satellite signal receiver upon occurrence of data transmission from the wireless transceiver;

wherein the gating further comprises disabling the signal integration in response to the percentage exceeding a predefined threshold and the control signal.

15. The method of claim 9, wherein signal integration comprises accumulation of signal correlations over a predefined period.

16. The method of claim 15, wherein signal integration further comprises accumulation of magnitudes of the signal correlations over a predefined period.

17. The method of claim 9, further comprising:

substantially holding a gain setting of an automatic gain control block within the satellite signal receiver in response to the percentage exceeding a pre-defined threshold.

18. The method of claim 9, further comprising:

driving a gain setting of an automatic gain control block within the satellite signal receiver to a pre-defined value in response to the percentage exceeding a pre-defined threshold.

19. A satellite signal receiver, comprising:

a front end for receiving satellite signals from a plurality of satellites and producing baseband signals;

a satellite signal processor for producing signal correlations between the baseband signals and pseudorandom reference codes;

accumulation circuitry for accumulating the signal correlations; and

a controller for receiving a control signal upon occurrence of data transmission from a wireless transceiver operating in proximity to the satellite signal receiver and providing a gate signal to the accumulation circuitry in response to the control signal, the gate signal operable to disable the accumulation circuitry.

20. The satellite signal receiver of claim 19, further comprising:

an automatic gain control circuit for controlling gain of the front end;

wherein the control signal is operable to substantially hold the gain.

21. The satellite signal receiver of claim 19, further comprising:

an automatic gain control circuit for controlling gain of the front end;

wherein the control signal is operable to drive the gain to a predefined value.

22. A satellite signal receiver, comprising:

an RF/IF converter for filtering and frequency translating received satellite signals to form an intermediate frequency (IF) signal;

an analog-to-digital converter for digitizing the IF signal;

a tuner for producing baseband signal from the digitized IF signal;

a satellite signal processor for producing signal correlations between the baseband signals and pseudorandom reference codes;

accumulation circuitry for accumulating the signal correlations;

a counter for counting signal samples of the digitized IF signal having one or more values of a plurality of possible values; and

a controller for monitoring a percentage of signal samples having the one or more values over a predefined period and providing a gate signal to the accumulation circuitry in response to the percentage exceeding a predefined threshold, the gate signal operable to disable the accumulation circuitry.

23. The satellite signal receiver of claim 22, wherein the controller is further configured to receive a control signal upon occurrence of data transmission from a wireless transceiver operating in proximity to the satellite signal receiver and provide the gate signal to the accumulation circuitry in response to the control signal.

24. The satellite signal receiver of claim 22, further comprising:

an automatic gain control circuit for controlling gain of the RF/IF converter;

wherein the gate signal is operable to substantially hold the gain.

25. The satellite signal receiver of claim 22, further comprising:

an automatic gain control circuit for controlling gain of the RF/IF converter;

wherein the gate signal is operable to drive the gain to a predefined value.

26. A method of controlling gain within a satellite signal receiver, comprising:

monitoring data transmission of a wireless transceiver operating in proximity to the satellite signal receiver;

transmitting a control signal to an automatic gain control circuit within the satellite signal receiver upon occurrence of data transmission from the wireless transceiver;

adjusting a gain setting of the automatic gain control circuit in response to the control signal.

27. The method of claim 27, wherein the adjusting comprises:

substantially holding the gain setting of the automatic gain control circuit in response to the control signal.

28. The method of claim 27, wherein the adjusting comprises:

driving the gain setting of the automatic gain control circuit to a predefined value in response to the control signal.

29. A method of controlling gain within a satellite signal receiver, comprising:

selecting one or more values of satellite signal samples from a plurality of possible values;

monitoring a percentage of satellite signal samples having the one or more selected values over a predefined period;

transmitting a gate signal to an automatic gain control circuit within the satellite signal receiver in response to the percentage exceeding a predefined threshold; and

adjusting a gain setting of the automatic gain control circuit using the gate signal.

30. The method of claim 29, wherein the adjusting comprises:

substantially holding the gain setting of the automatic gain control circuit.

31. The method of claim 29, wherein the adjusting comprises:

driving the gain setting of the automatic gain control circuit to a predefined value.