Physical and MAC adaptation for interference mitigation with cognitive radio

• US 8,301,081 B2
• Filed: 11/13/2007
• Issued: 10/30/2012
• Est. Priority Date: 11/13/2007
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Aboba, Bernard D., Bahl, Paramvir, Narlanka, Gopala S., Padhye, Jitendra D., Radunovic, Bozidar, Ramjee, Ramachandran, Tan, Kun, Temudo de Castro, Miguel Oom
• Primary Examiner(s): HUANG, WEN WU
• Application Number:
  US11/939,217
• Publication Number:
  US 20090124205A1
• Time in Patent Office: 1,813 Days
• Field of Search: 455 411- 3, 455/63.1, 455/114.2, 455/278.1, 455/296
• US Class Current: 455/41.2
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04B 17/382 for resource allocation, admission control or handover

Abstract

A communication device cognitively monitors interference signals across a communication band so that adaptations for physical and medium access control (MAC) of data packet transmissions are appropriate for a particular interference signal. Characteristics of an interference signal of interest (e.g., bandwidth, power and/or duration relative to an average data packet transmitted over a communication channel of the communication device) are sensed for an appropriate adaptation (e.g., forward error correction, modulation technique, back off, request to send/clear to send protocol, etc.). Patterns for known types of interference sources can be compared so that when recognized an associated adaptation can be used.

Claims

1. A wireless device, comprising:

a transmitter for digital wireless transmission on one of a plurality of communication channels of a communication band;

a cognitive radio sensor for monitoring radio frequencies across the communication band;

an interference module configured to;

characterize an interference signal sensed by the cognitive radio sensor;

reference a stored interference patterns data structure to compare and match the characterized interference signal with a stored interference pattern; and

select an adaptation for the characterized interference signal from a plurality of different tailored adaptations when the characterized interference signal is recognized based on the comparison and matching, wherein at least a first tailored adaptation includes a mitigating technique that is not included in a second tailored adaptation; and

a communication module for physical layer and medium access control (MAC) layer control that mitigates the characterized interference signal with the selected adaptation.

2. The wireless device of claim 1, wherein the stored interference patterns data structure contains patterns of different types of interference.

3. The wireless device of claim 2, wherein the different types of interference each comprise a selected modulation pattern from a group consisting of a television signal, a wireless access point, a wireless personal area networks device, a radio microphone, and a wireless terminal.

4. The wireless device of claim 2, wherein the patterns comprise a pilot signal, a lobe bandwidth size and time-sequence of signal.

5. The wireless device of claim 1, wherein characteristics of the interference signal are stored for persistent adaptation.

6. The wireless device of claim 5, further comprising a location module for determining a location pertaining to the interference signal for persistent adaptation.

7. The wireless device of claim 1, wherein the interference module characterizes the interference signal as narrowband relative to a channel bandwidth utilized by the transmitter and selects increased forward error correction as a tailored adaptation.

8. The wireless device of claim 1, wherein the interference module characterizes the interference signal as a wideband interference signal relative to channel bandwidth and as low power relative to a physical layer power setting of the transmitter.

9. The wireless device of claim 8, wherein the selected adaptation is selected from a group consisting of trading away data rate for a more robust modulation scheme, trading away data rate for a more robust forward error correction coding scheme, and increasing transmit power.

10. The wireless device of claim 1, wherein the interference module characterizes a duration of the interference signal relative to a data transmission segment, and selects a change of channel tailored adaptation in response to a determination of a long term duration interference signal.

11. The wireless device of claim 10, wherein characterizing the duration as short term or long term depends upon a threshold defined as ten times an amount of time necessary to send an average data packet.

12. The wireless device of claim 10, wherein in response to a determination of a short-term duration interference signal and a further determination of an IEEE 802.11 hidden terminal creating the interference signal, the communication module enables request to send and clear to send (RTS/CTS) protocol.

13. The wireless device of claim 10, wherein in response to a determination of a short-term duration interference signal, the interference module selects a back off tailored adaptation.

14. The wireless device of 1, wherein the interference module characterizes the interference signal of interest to ascertain power, duration and bandwidth size.

15. A method of mitigating interference, comprising:

transmitting on a wireless digital packet communication channel of a plurality of channels of a communication band,

monitoring power and duration of radio frequencies across the communication band;

characterizing an interference signal;

comparing the characterization of the interference signal to a plurality of different patterns to recognize the interference signal;

selecting a communication adaptation for physical layer and medium access control (MAC) layer control based on the interference characterization, wherein the communication adaptation is selected from a plurality of different communication adaptations that do not have a common communication mitigating technique across the entire plurality.

16. The method of claim 15, wherein the communication adaptation is increased forward error correction adaptation selected in response to a narrowband characterization of the interference signal.

17. The method of claim 15, wherein the communication adaptation is a more robust modulation or forward error coding adaptation selected in response to a wideband, low power characterization of the interference signal.

18. The method of claim 15, wherein the communication adaptation is an avoidance adaptation in response to a long duration, high power, wideband characterization of the interference signal.

19. The method of claim 15, wherein the communication adaptation enables a request to send, clear to send (RTS/CTS) protocol adaptation selected in response to a wideband, high power, short duration characterization of the interference signal.

20. The method of claim 15, wherein the communication adaptation is a back off adaption selected in response to a wideband, high power, short duration and hidden terminal characterization of the interference signal.

21. The method of claim 15, wherein comparing the characterization further comprises the characterization including type, duration, and power.

22. A method of mitigating interference, comprising:

transmitting on a wireless digital packet communication channel of a plurality of channels of a communication band;

monitoring power and duration of radio frequencies across the communication band;

characterizing an interference signal as at least one of;

an interference narrowband signal;

an interference, wideband signal with a low power level relative to a physical layer power setting of a communication device;

an interference, long term, wideband signal with a high power level relative to the physical layer power setting of the communication device; and

pattern matching the characterized interference signal with at least one adaptation, wherein;

when the interference signal is the interference narrowband signal, the at least one adaptation increases forward error correction;

when the interference signal is the interference, wideband signal with a low power level relative to the physical layer power setting of the communication device, the at least one adaptation is selected from i) switching to a more robust modulation scheme, or ii) increasing transmission power, or a combination thereof; and

when the interference signal is the interference, long term, wideband signal with a high power level relative to the physical layer power setting of the communication device, the at least one adaptation is selected from i) changing channels, or ii) increasing transmission power, or a combination thereof.