Methods and apparatus for detecting presence of a jamming signal

• US 9,621,207 B2
• Filed: 08/06/2012
• Issued: 04/11/2017
• Est. Priority Date: 08/06/2012
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Inventors: Alberth, Jr., William P., Welnick, William E., Declerck, Daniel J.
• Primary Examiner(s): Kim, Wesley
• Assistant Examiner(s): Shiue, Dong-Chang
• Application Number:
  US13/567,219
• Publication Number:
  US 20140038536A1
• Time in Patent Office: 1,709 Days
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal

Abstract

A communication device performs a method for detecting presence of a jamming signal. The method includes retrieving a scan list comprising multiple radio channels within a first frequency range of operation of the communication device. The method further includes scanning at least a subset of the channels on the scan list to determine, for each scanned channel, whether energy that exceeds an energy threshold is detected on the scanned channel. Moreover, the method includes determining a first quantitative measure based on a first plurality scanned channels having energy that exceeds the energy threshold, and comparing the first quantitative measure to at least a first jamming signal detection threshold. Additionally, the method includes indicating, on the communication device, presence of a jamming signal when the first quantitative measure satisfies the at least a first jamming signal detection threshold.

Claims

1. A method, performed in a communication device, for detecting presence of a jamming signal, the method comprising:

retrieving a scan list comprising multiple radio channels within a first frequency range of operation of the communication device;

scanning a subset of the channels on the scan list to determine, for each scanned channel, whether energy that exceeds an energy threshold is detected on the scanned channel;

determining a first quantitative measure of a first plurality of the scanned subset of the channels having energy that exceeds the energy threshold;

comparing the first quantitative measure to at least a first jamming signal detection threshold;

indicating, on the communication device, presence of a jamming signal when the first quantitative measure satisfies the at least the first jamming signal detection threshold;

when the first quantitative measure fails to satisfy the at least the first jamming signal detection threshold, comparing a second quantitative measure to at least a second jamming signal detection threshold, wherein the second quantitative measure is determined based on a second plurality of the scanned subset of the channels having energy that exceeds the energy threshold; and

indicating, on the communication device, presence of the jamming signal when the second quantitative measure satisfies the at least the second jamming signal detection threshold.

2. The method of claim 1, wherein the communication device is configured to communicate, within the first frequency range, a signal having a first bandwidth, and wherein the jamming signal has a second bandwidth that is greater than the first bandwidth.

3. The method of claim 1, wherein the first quantitative measure comprises a ratio of a total number of scanned channels having energy that exceeds the energy threshold to a total number of scanned channels.

4. The method of claim 1, wherein the first quantitative measure comprises a highest number of consecutive scanned channels having energy that exceeds the energy threshold.

5. The method of claim 1, wherein the first quantitative measure comprises a combination of average energy and standard deviation of energy detected across all scanned channels.

6. The method of claim 1 further comprising indicating, to an external device, the presence of the jamming signal and a geographic position of the communication device when the first quantitative measure satisfies the at least the first jamming signal detection threshold.

7. The method of claim 6, wherein indicating the absence of the jamming signal to the external device is performed after the jamming signal is no longer detected.

8. The method of claim 6, wherein the jamming signal is present on a first set of channels within the first frequency range, and the presence of the jamming signal is indicated to the external device using a second set of channels that is different than the first set of channels.

9. The method of claim 1, wherein the presence of the jamming signal is indicated on the communication device using at least one of color, sound, or graphics.

10. The method of claim 1, wherein the scanned channels comprise at least one unassigned channel.

11. The method of claim 1, wherein retrieving the scan list is performed in response to a loss of radio communication service to the communication device.

12. The method of claim 11, wherein retrieving the scan list is automatically triggered upon the loss of radio communication service to the communication device.

13. The method of claim 1, wherein retrieving the scan list is triggered by user input into a user interface of the communication device.

14. The method of claim 1 furthering comprising:

when the second quantitative measure fails to satisfy the at least the second jamming signal detection threshold, comparing a third quantitative measure to at least a third jamming signal detection threshold, wherein the third quantitative measure is determined based on a third plurality of the scanned subset of the channels having energy that exceeds the energy threshold; and

indicating, on the communication device, presence of the jamming signal when the third quantitative measure satisfies the at least the third jamming signal detection threshold.

15. The method of claim 14, wherein:

the first quantitative measure comprises a ratio of a total number of scanned channels having signal strength that exceeds a signal strength threshold to a total number of scanned channels;

the second quantitative measure comprises a highest number of consecutive scanned channels having signal strength that exceeds the signal strength threshold; and

the third quantitative measure comprises a combination of average signal strength and standard deviation of signal strength detected across all scanned channels.

16. A communication device for detecting, within a first frequency range of operation of the communication device, presence of a jamming signal having a first bandwidth, the communication device comprising:

a network interface configured to;

communicate, within the first frequency range, at least one signal having a second bandwidth that is less than the first bandwidth;

retrieve a scan list comprising multiple radio channels within the first frequency range; and

scan at least a subset of the radio channels on the scan list to detect signal strength on each scanned radio channel;

a processing device coupled to the network interface and configured to;

compare each detected signal strength to a signal strength threshold to determine all scanned channels having a detected signal strength that exceeds the signal strength threshold;

derive a first one of multiple quantitative measures of a first plurality of the scanned the at least the subset of the radio channels having a detected signal strength that exceeds the signal strength threshold;

compare the first one of the derived multiple quantitative measures to a first jamming signal detection threshold to determine presence of the jamming signal within the first frequency range;

when the first one of the derived multiple quantitative measures fails to satisfy the first jamming signal detection threshold, compare a second one of the derived multiple quantitative measures to a second jamming signal detection threshold, wherein the second one of the derived multiple quantitative measures is determined based on a second plurality of the scanned the at least the subset of the radio channels having a detected signal strength that exceeds the signal strength threshold; and

a user interface coupled to the processing device and configured to provide an indication of the presence of the jamming signal when the first one of the derived multiple quantitative measures satisfies the first jamming signal detection threshold, and when the second one of the derived multiple quantitative measures satisfies the second jamming signal detection threshold, wherein the user interface is configured to provide the indication of the presence of the jamming signal using at least one of color, sound, or a graph.

17. The communication device of claim 16 further comprising a location device coupled to the network interface and configured to determine a location of the communication device when the first one of the derived multiple quantitative measures satisfies the first jamming signal detection threshold, wherein the communication device is configured to provide, to a second device using the network interface, the indication of the presence of the jamming signal and the location of the communication device.

18. The communication device of claim 16, wherein the multiple quantitative measures comprises at least two of:

a ratio of a total number of scanned channels having signal strength that exceeds the signal strength threshold to a total number of scanned channels;

a highest number of consecutive scanned channels having signal strength that exceeds the signal strength threshold;

or a combination of average signal strength and standard deviation of signal strength detected across all scanned channels.

19. A non-transient computer-readable storage element having computer readable code stored thereon for programming a computer to perform a method for detecting presence of a jamming signal, the method comprising:

retrieving a scan list of channels within a frequency band of operation of the communication device, wherein the retrieving is performed in response to a loss of radio communication service to the communication device;

scanning multiple channels on the scan list to determine scanning results indicating, for each scanned channel, whether energy that exceeds an energy threshold is detected on the channel;

determining, based on the scanning results, a ratio of a total number of scanned channels having energy that exceeds the energy threshold to a total number of scanned channels and a highest number of consecutive scanned channels having energy that exceeds the energy threshold;

determining presence of a jamming signal when the ratio exceeds a confidence threshold;

otherwise determining presence of the jamming signal when the highest number of consecutive scanned channels having energy that exceeds the energy threshold exceeds a threshold detection count;

otherwise, determining, based on the scanning results, a combination of average energy and standard deviation of energy detected across all scanned channels, and determining presence of the jamming signal when the average energy exceeds an average energy threshold and the standard deviation is below a standard deviation.

20. A communication device for detecting, within a first frequency range of operation of the communication device, presence of a jamming signal having a first bandwidth, the communication device comprising:

a network interface configured to;

communicate, within the first frequency range, at least one signal having a second bandwidth that is less than the first bandwidth;

retrieve a scan list comprising multiple radio channels within the first frequency range; and

scan at least a subset of the radio channels on the scan list to detect signal strength on each scanned radio channel;

a processing device coupled to the network interface and configured to;

compare each detected signal strength to a signal strength threshold to determine all scanned channels having a detected signal strength that exceeds the signal strength threshold;

derive at least one of multiple quantitative measures of a plurality of the scanned the at least the subset of the radio channels having a detected signal strength that exceeds the signal strength threshold; and

compare each derived quantitative measure to a corresponding jamming signal detection threshold to determine presence of the jamming signal within the first frequency range;

a location device coupled to the network interface and configured to determine a location of the communication device when the at least one of the derived quantitative measures satisfies the corresponding jamming signal detection threshold, wherein the communication device is configured to provide, to a second device using the network interface, the indication of the presence of the jamming signal and the location of the communication device; and

a user interface coupled to the processing device and configured to provide an indication of the presence of the jamming signal when at least one of the derived quantitative measures satisfies the corresponding jamming signal detection threshold, wherein the user interface is configured to provide the indication of the presence of the jamming signal using at least one of color, sound, or a graph.

21. A communication device for detecting, within a first frequency range of operation of the communication device, presence of a jamming signal having a first bandwidth, the communication device comprising:

a network interface configured to;

communicate, within the first frequency range, at least one signal having a second bandwidth that is less than the first bandwidth;

retrieve a scan list comprising multiple radio channels within the first frequency range; and

scan at least a subset of the radio channels on the scan list to detect signal strength on each scanned radio channel;

a processing device coupled to the network interface and configured to;

compare each detected signal strength to a signal strength threshold to determine all scanned channels having a detected signal strength that exceeds the signal strength threshold;

derive at least one of multiple quantitative measures of a plurality of the scanned the at least the subset of the radio channels having a detected signal strength that exceeds the signal strength threshold;

compare each derived quantitative measure to a corresponding jamming signal detection threshold to determine presence of the jamming signal within the first frequency range; and

wherein the multiple quantitative measures comprises at least two of;

a ratio of a total number of scanned channels having signal strength that exceeds the signal strength threshold to a total number of scanned channels;

a highest number of consecutive scanned channels having signal strength that exceeds the signal strength threshold;

or a combination of average signal strength and standard deviation of signal strength detected across all scanned channels; and

a user interface coupled to the processing device and configured to provide an indication of the presence of the jamming signal when at least one of the derived quantitative measures satisfies the corresponding jamming signal detection threshold, wherein the user interface is configured to provide the indication of the presence of the jamming signal using at least one of color, sound, or a graph.