Systems and Methods for Dynamic Frequency Selection for Interference Avoidance

• US 20140220964A1
• Filed: 02/06/2013
• Published: 08/07/2014
• Est. Priority Date: 02/06/2013
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (General Electric Company)
• Original Assignee: General Electric Company
• Inventors: Kurucz, Paul Jr., Vilagy, Jonathan M., Charissis, Alexandros A.
• Granted Patent: US 9,408,087 B2
• Time in Patent Office: Days
• US Class Current: 455/423
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 72/54 based on quality criteria

Abstract

Systems and methods for identifying interference that warrants dynamic frequency selection (DFS) are provided. In one example, a wireless data radio system includes a radio frequency receiver and thresholding circuitry. The radio frequency receiver may provide a received signal strength indicator. The thresholding circuitry may compare the received signal strength indicator to a threshold value associated with radio interference, determine whether a dynamic frequency selection operation is warranted based at least in part on the comparison, and output a dynamic frequency selection signal indicating whether the dynamic frequency selection operation is warranted.

Claims

1. A wireless radio system comprising:

a radio frequency receiver configured to provide a received signal strength indicator; and

thresholding circuitry configured to;

compare the received signal strength indicator to a threshold value associated with radio interference;

determine whether a dynamic frequency selection operation is warranted based at least in part on the comparison; and

output a dynamic frequency selection signal indicating whether the dynamic frequency selection operation is warranted.

2. The system of claim 1, wherein the thresholding circuitry is configured to:

sample the comparison of the received signal strength indicator and the threshold value over time to obtain a bit stream;

compare the bit stream to at least one radar signal signature; and

determine that the dynamic frequency selection operation is warranted when at least part of the bit stream substantially matches the at least one radar signal signature.

3. The system of claim 1, wherein the thresholding circuitry is configured to perform the dynamic frequency selection operation when the comparison indicates that the received signal strength indicator exceeds the threshold value.

4. The system of claim 1, wherein the received signal strength indicator and the threshold value comprise analog values.

5. The system of claim 4, comprising a digital-to-analog converter configured to receive a digital threshold value from a communications processor, convert the digital threshold value into the threshold value, and provide the threshold value to the thresholding circuitry.

6. The system of claim 4, wherein the thresholding circuitry comprises a threshold comparator configured to compare the received signal strength indicator to the threshold value.

7. The system of claim 1, wherein the thresholding circuitry comprises a microcontroller.

8. The system of claim 1, comprising a communications processor configured to perform the dynamic frequency selection operation or to cause another wireless radio system to perform the dynamic frequency selection operation based at least in part on the dynamic frequency selection signal, wherein the communications processor comprises a system-on-a-chip and the thresholding circuitry is external to the communications processor.

9. The system of claim 1, wherein the system is configured to comply with the ETSI EN 302 502 specification.

10. The system of claim 1, wherein the system is configured to comply with the FCC Part 90 specification.

11. One or more tangible non-transitory machine-readable media comprising instructions to:

receive a radio frequency received signal strength indicator from a radio frequency receiver;

receive a control signal from a communications processor during an interference-testing period of an ongoing communication frame during which neither a base station nor a subscriber station of a wireless data radio system is communicating;

upon receipt of the control signal, compare the radio frequency received signal strength indicator to a threshold value;

determine whether a dynamic frequency selection operation is warranted based at least in part on the comparison; and

output a digital signal indicating whether the dynamic frequency selection operation is warranted.

12. The one or more machine-readable media of claim 11, wherein the instructions to determine whether to perform a dynamic frequency selection operation comprise instructions to:

sample the comparison multiple times during the interference test period to obtain a bit stream;

compare at least part of the bit stream to at least one defined radar signal signature;

when the at least part of the bit stream substantially matches the at least one defined radar signal signature, determine that the dynamic frequency selection is warranted; and

when the at least part of the bit stream substantially does not match the at least one defined radar signal signature, determine that the dynamic frequency selection is not warranted.

13. The one or more machine-readable media of claim 11, wherein the instructions to determine whether to perform a dynamic frequency selection operation comprise instructions to:

when the comparison indicates that the radio frequency received signal strength indicator exceeds the threshold value, determine that the dynamic frequency selection is warranted; and

when the comparison does not indicate that the radio frequency received signal strength indicator exceeds the threshold value, determine that the dynamic frequency selection is not warranted.

14. The one or more machine-readable media of claim 11, wherein the instructions are configured to be executed by processing circuitry of the base station and wherein the instructions comprise instructions to cause the base station to perform dynamic frequency selection when the dynamic frequency selection is determined to be warranted.

15. The one or more machine-readable media of claim 11, wherein the instructions are configured to be executed by processing circuitry of the subscriber station and wherein the instructions comprise instructions to issue a communication to the base station to cause the base station to perform the dynamic frequency selection when the dynamic frequency selection is determined to be warranted.

16. A wireless data radio system comprising:

a base station configured to communicate with at least one subscriber station over a communication frame;

wherein the communication frame comprises;

a downlink period for communication from the base station to the at least one subscriber station;

an uplink period for communication from the at least one subscriber station to the base station; and

an interference test period during which neither the base station nor the at least one subscriber station is communicating; and

wherein the base station is configured to identify whether radio interference is occurring during the interference test period that indicates a need to perform a dynamic frequency selection operation.

17. The system of claim 16, wherein the interference test period is configured to occur before the downlink period and the uplink period.

18. The system of claim 16, wherein the interference test period is configured to occur between the downlink period and the uplink period.

19. The system of claim 16, wherein the interference test period is configured to occur after the downlink period and the uplink period.

20. The system of claim 16, comprising the at least one subscriber station, wherein the at least one subscriber station is configured to:

communicate with the base station using the communication frame;

identify whether radio interference is occurring during the interference test period that indicates the need to perform the dynamic frequency selection operation; and

when the radio interference is identified, communicate an indication to the base station to cause the base station to perform the dynamic frequency selection operation.