Cognitive multi-user OFDMA

• US 9,065,687 B2
• Filed: 03/22/2012
• Issued: 06/23/2015
• Est. Priority Date: 12/12/2006
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Huitema, Christian, Hassan, Amer A.
• Primary Examiner(s): Fan, Chieh M
• Assistant Examiner(s): Hassan, Sarah
• Application Number:
  US13/427,494
• Publication Number:
  US 20120182875A1
• Time in Patent Office: 1,188 Days
• Field of Search: 375/148, 375/295, 370/248
• US Class Current: 1/1
• CPC Class Codes: H04J 1/12 Arrangements for reducing cross-talk between channels in line transmission systems H04B3/32; in cables or lines H04B3/26 - H04B3/30
• CPC Class Codes: H04J 1/16 Monitoring arrangements for transmission in general H04B17/00; for amplifiers H03F1/52, H03F1/523
• CPC Class Codes: H04J 11/003 at the transmitter transmission to multiple receive units in multiple input multiple output [MIMO] H04B7/0452; transmit antenna weighting H04B7/0615
• CPC Class Codes: H04J 11/0066 of narrowband interference narrowband interference reduction H04B1/1036
• CPC Class Codes: H04L 27/0006 Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio for spectrum sharing between different networks H04W16/14
• CPC Class Codes: H04L 27/16 Frequency regulation arrangements
• CPC Class Codes: H04L 27/2627 Modulators
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0016 Time-frequency-code
• CPC Class Codes: H04L 5/0032 Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0039 Frequency-contiguous, i.e. with no allocation of frequencies for one user or terminal between the frequencies allocated to another
• CPC Class Codes: H04L 5/0058 Allocation criteria
• CPC Class Codes: H04L 5/0064 Rate requirement of the data, e.g. scalable bandwidth, data priority
• CPC Class Codes: H04L 5/0073 Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning

Abstract

A computing device operating according to a frequency division multiplexed protocol in which communication occurs over a signal formed from a plurality of sub-channels selected from anywhere in a frequency spectrum. A computing device may select sub-channels cognitively by using information about sub-channels previously deemed suitable or unsuitable by that computing device or other computing devices. A described technique for determining sub-channel suitability includes analyzing radio frequency energy in the sub-channel to detect signals generated by another computing device or high noise levels. Information may also be used to cognitively select sub-channels to be analyzed, such as by first selecting for analysis previously-used sub-channels.

Claims

1. A method of operating a computing device for communication using a frequency-division multiplexing protocol, the method comprising:

selecting, for communicating a signal, a first plurality of sub-channels collectively having a first bandwidth, the first plurality being selected from a second plurality of sub-channels, the second plurality collectively having a second bandwidth, the second bandwidth being greater than the first bandwidth, wherein selecting the first plurality of sub-channels comprises preferentially selecting a sub-channel when the sub-channel was previously selected for carrying a previous signal communicated by the computing device, the previous signal being different from the signal;

communicating the signal using the first plurality of sub-channels; and

retrieving an indication of sub-channels previously selected for carrying the previous signal, where the indication comprises a listing of sub-channels selected during one or more prior performances of the retrieving, selecting, and communicating.

2. The method of claim 1, where the selecting the first plurality of sub-channels comprises:

(A) determining a number of sub-channels based on a desired data rate;

(B) examining a sub-channel of the second plurality of sub-channels to determine whether the sub-channel has conditions unsuitable to data transmission;

(C) identifying the sub-channel as suitable for communication or identifying the sub-channel as unsuitable for communication according to a determination of act (B), and selecting the sub-channel for communication if it has been identified as suitable; and

(D) repeating acts (B) and (C) for different sub-channels of the second plurality of sub-channels until at least the number of sub-channels is selected.

3. The method of claim 2, where the act (D) further comprises storing an indication of the first plurality of sub-channels selected.

4. The method of claim 2, where

the act (D) further comprises storing an indication of sub-channels identified as unsuitable for communication;

and

the act (B) further comprises examining a sub-channel previously identified as unsuitable after other sub-channels not previously identified as unsuitable if the computing device attempts to create a new signal within a period of time of storing the indication of sub-channels identified as unsuitable.

5. The method of claim 2, where the act (B) further comprises choosing a sub-channel to examine by one of a random selection process or a linear sequential selection process.

6. The method of claim 2, where the act (B) further comprises examining the sub-channel for a predetermined period of time before making the determination.

7. The method of claim 1, where the communicating:

transmitting a first selection notice to at least one other computing device, the first selection notice comprising a notification that the computing device has selected the first plurality of sub-channels; and

when a second selection notice is received from another computing device, refraining from selecting choosing sub-channels listed in the second selection notice received from the other computing device for a predetermined period of time.

8. The method of claim 1, where:

the selecting is performed once at the beginning of a communication session, and

the method further comprises releasing the first plurality of sub-channels at the end of the communication session.

9. The method of claim 8, where a communication session is a discrete data transmission.

10. A method of communicating between a first computing device and a second computing device, the method comprising:

with the first computing device, selecting, for carrying at least one message, a first plurality of sub-channels collectively having a first bandwidth, the first plurality of sub-channels being selected from a second plurality of sub-channels, the second plurality of sub-channels collectively having a second bandwidth, the second bandwidth greater than the first bandwidth, wherein selecting the plurality of selected sub-channels comprises preferentially selecting a sub-channel when the sub-channel was previously selected by the first computing device for carrying a previous signal transmitted by the first computing device, the previous signal being different from the signal; and

communicating the at least one message over the first plurality of sub-channels; and

retrieving an indication of sub-channels previously selected for carrying the previous signal, where the indication comprises a listing of sub-channels selected during one or more prior performances of the retrieving, selecting, and communicating.

11. The method of claim 10, where communicating the at least one message over the first plurality of sub-channels comprises receiving a message from the second computing device at the first computing device.

12. The method of claim 10, further comprising transmitting from the first computing device to the second computing device an identification of the first plurality of sub-channels prior to the act of transmitting the at least one message.

13. The method of claim 10, further comprising transmitting, from the first computing device to the second computing device, signals via the first plurality of sub-channels to identify to the second computing device that the first plurality of sub-channels have been selected.

14. The method of claim 10, further comprising determining a third plurality of sub-channels via which to receive a signal transmitted by the second computing device, the third plurality of sub-channels having been selected by the second computing device, the determining comprising examining sub-channels previously used for communication between the first computing device and the second computing device and analyzing signals received on the sub-channels previously used prior to examining signals received on other sub-channels not previously used.

15. A system comprising a computing device and at least one program module that are together configured for performing actions for communication using a frequency-division multiplexing protocol, the actions comprising:

selecting, for communicating a signal, a first plurality of sub-channels collectively having a first bandwidth, the first plurality being selected from a second plurality of sub-channels, the second plurality collectively having a second bandwidth, the second bandwidth being greater than the first bandwidth, wherein selecting the first plurality of sub-channels comprises preferentially selecting a sub-channel when the sub-channel was previously selected for carrying a previous signal communicated by the computing device, the previous signal being different from the signal;

communicating the signal using the first plurality of sub-channels; and

retrieving an indication of sub-channels previously selected for carrying the previous signal, where the indication comprises a listing of sub-channels selected during one or more prior performances of the retrieving, selecting, and communicating.

16. The system of claim 15, where the selecting the first plurality of sub-channels comprises:

(A) determining a number of sub-channels based on a desired data rate;

(B) examining a sub-channel of the second plurality of sub-channels to determine whether the sub-channel has conditions unsuitable to data transmission; and

(C) identifying the sub-channel as suitable for communication or identifying the sub-channel as unsuitable for communication according to a determination of act (B), and selecting the sub-channel for communication if it has been identified as suitable;

(D) repeating acts (B) and (C) for different sub-channels of the second plurality of sub-channels until at least the number of sub-channels is selected.

17. The system of claim 16, where the act (D) further comprises storing an indication of the first plurality of sub-channels selected.

18. The system of claim 16, where the act (B) further comprises choosing a sub-channel to examine by one of a random selection process or a linear sequential selection process.

19. The system of claim 16, where the act (B) further comprises examining the sub-channel for a predetermined period of time before making the determination.