Method and apparatus for mitigating interference in a satellite signal receiver

• US 8,571,153 B2
• Filed: 04/14/2010
• Issued: 10/29/2013
• 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
• Primary Examiner(s): Malek, Leila
• Application Number:
  US12/759,816
• Publication Number:
  US 20100203827A1
• Time in Patent Office: 1,294 Days
• Field of Search: 375/346, 375/144, 375/148, 375/348, 455/3.02, 455/1, 455/63.1, 455/114.2, 455/296
• 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, a control signal is transmitted to the satellite signal receiver upon occurrence of data transmission from a wireless transceiver operating in proximity to the satellite signal receiver. Signal integration within the satellite signal receiver is gated in response to the control signal. In another example, one or more values of satellite signal samples are selected from a plurality of possible values. Signal integration within the satellite signal receiver is gated in response to a percentage of satellite signal samples taken over a predefined period 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, comprising:

monitoring a 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 the data transmission from the wireless transceiver, the control signal including information indicative of signal power associated with the data transmission;

driving a gain setting of an automatic gain control (AGC) block to a non-zero predefined value in response to the control signal;

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

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

2. The method of claim 1, wherein the

control signal has a first state associated with the signal power exceeding the predefined threshold, and a second state associated with the signal power being below the predefined threshold.

3. The method of claim 1, further comprising:

gating accumulation of satellite signal correlations over a predefined period.

4. The method of claim 3, wherein the gating accumulation of satellite signal correlations comprises:

gating accumulation of in-phase satellite signal correlations and quadrature phase satellite signal correlations over the predefined period.

5. The method of claim 3, wherein the gating accumulation of satellite signal correlations comprises:

gating accumulation of values indicative of a magnitude or a power of the satellite signal correlations over the predefined period.

6. The method of claim 1, further comprising:

holding the gain setting in response to the control signal.

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

gating accumulation of successive sets of satellite signal correlations over a predetermined interval.

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

selecting a value of a satellite signal sample from a plurality of possible values;

monitoring a percentage of satellite signal samples corresponding to the selected value over a predefined period;

disabling accumulation of magnitudes of satellite signal correlations over the predefined period within the satellite signal receiver in response to the percentage exceeding a predefined threshold; and

enabling the accumalation of magnitudes of the satellite signal correlations over the predefined period in response to the percentage being below the predefined threshold.

9. The method of claim 8, wherein the selecting comprises:

selecting the value having a sign bit and a magnitude bit.

10. The method of claim 8, wherein the selecting comprises:

selecting the value having a logically high magnitude bit.

11. The method of claim 8, wherein the predefined threshold is 60%.

12. The method of claim 8, further comprising:

monitoring a 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 the data transmission from the wireless transceiver, and

wherein the disabling further comprises;

disabling the accumulation in response to;

the percentage exceeding the predefined threshold; and

receipt of the control signal.

13. The method of claim 8, further comprising:

holding a gain setting of an automatic gain control (AGC) block in response to the percentage exceeding the predefined threshold.

14. The method of claim 8, further comprising:

driving a gain setting of an automatic gain control (AGC) block to a predefined value in response to the percentage exceeding the predefined threshold.

15. A satellite signal receiver, comprising:

a front end configured to receive satellite signals from a plurality of satellites and to produce baseband signals;

an automatic gain control (AGC) block configured to control a gain of the front end;

a signal processor configured to produce satellite signal correlations between the baseband signals and pseudorandom reference codes;

an accumulator configured to accumulate the satellite signal correlations; and

a controller configured to;

receive a control signal upon occurrence of a data transmission from a wireless transceiver operating in proximity to the satellite signal receiver;

provide a gate signal to the accumulator in response to the control signal, the control signal including information indicative of a signal power of the data transmission; and

enable the AGC block to drive the gain to a non-zero predefined value;

wherein the accumulator is further configured to disable accumulation of the satellite signal correlations in response to the control signal indicating that the signal power exceeds a predefined threshold, and to enable the accumulation of the satellite signal correlations in response to the control signal indicating that the signal power is below the predefined threshold.

16. The satellite signal receiver of claim 15, wherein the control signal further enables the AGC block to hold the gain.

17. A satellite signal receiver, comprising:

A Radio Frequency/Intermediate Frequency (RF/IF) converter configured to filter and frequency translate received satellite signals to form IF signals;

an analog-to-digital converter configured to digitize the IF signals;

a tuner configured to produce baseband signals from the digitized IF signals;

a signal processor configured to produce satellite signal correlations between the baseband signals and pseudorandom reference codes;

an accumulator configured to accumulate the satellite signal correlations;

a counter configured to count satellite signal samples of the digitized IF satellite signals having a value selected from a plurality of possible values; and

a controller configured to monitor a percentage of the satellite signal samples corresponding to the selected value over a predefined period and to provide a gate signal to the accumulator in response to the percentage exceeding a predefined threshold,

wherein the accumulator is further configured to disable accumulation of the satellite signal correlations upon receipt of the gate signal.

18. The satellite signal receiver of claim 17, wherein the controller is further configured to receive a control signal upon occurrence of a data transmission from a wireless transceiver operating in proximity to the satellite signal receiver and to provide the gate signal to the accumulator in response to the control signal.

19. The satellite signal receiver of claim 17, further comprising:

an automatic gain control (AGC) block configured to control a gain of the RF/IF converter,

wherein the gate signal enables the AGC block to hold the gain.

20. The satellite signal receiver of claim 17, further comprising:

an automatic gain control circuit (AGC) block configured to control a gain of the RF/IF converter, wherein the gate signal enables the AGC block to drive the gain to a predefined value.

21. The satellite signal receiver of claim 17, wherein the accumulator is further configured to stop accumulation of the satellite signal correlations such that the gated correlations are not accumulated with previous satellite signal correlations.