RANDOM ACCESS HETEROGENEOUS MIMO NETWORK

• US 20130064114A1
• Filed: 07/31/2012
• Published: 03/14/2013
• Est. Priority Date: 07/31/2011
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Katabi, Dina, Lin, Ching-Ju, Gollakota, Shyamnath
• Granted Patent: US 9,225,402 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04B 5/28 using the near field of leaky cables, e.g. of leaky coaxial cables
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• 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

Abstract

A number of techniques, which may be used together, provide distributed coordination of multiple stations so that concurrent transmissions and increased throughput are achieved on a shared radio medium. Each of the techniques provides a separate innovation that can be used alone or in combination with one or more of the other techniques.

Claims

1. A communication method comprising:

monitoring one or more transmissions received at multiple antennas over a communication medium;

determining a first relationship between signals received from the antenna; and

determining whether the determined relationship is compatible with transmission of an information bearing signal via the multiple antennas concurrently with the one or more transmissions.

2. The method of claim 1 wherein the communication medium comprises a radio communication medium.

3. The method of claim 1 comprises determining a dimensionality of one or more transmission.

4. The method of claim 3 wherein determining the dimensionality comprises determining a number of data streams.

5. The method of claim 3 wherein determining the dimensionality comprises determining a dimensionality of transmissions without requiring decoding of said transmissions.

6. The method of claim 1 wherein determining whether the determined relationship is compatible comprises determining whether a number of antennas exceeds a dimensionality of the one or more transmissions.

7. The method of claim 6 wherein the number of antennas comprises at least one of a number of antennas available for transmitting and a number of antennas available for receiving the transmission.

8. The method of claim 1 further comprising:

determining a second relationship between signals for transmission via each of the multiple antennas according to the determined first relationship between signals received from the antenna; and

sending a transmission from said antennas according to the determined second relationship concurrently with the one or more transmissions on the medium.

9. (canceled)

10. (canceled)

11. A communication method comprising:

determining a first relationship between signals received at multiple antennas of a first station from one or more transmissions over a communication medium;

determining a second relationship between signals suitable for reception of an information bearing transmission at said antennas concurrently with said one or more transmissions; and

sending information over the medium from the station sufficient for another multiple antenna system to form a transmission that matches the second relationship.

12. The method of claim 11 further comprising receiving a request to transmit from the other station, and in response sending the information as an indication that the other station is clear to send a concurrent transmission to the first station according to the second relationship.

13. The method of claim 12 further comprising receiving the concurrent transmission and cancelling an effect of the one or more transmissions.

14. The method of claim 11 wherein sending the information over the medium comprises broadcasting said information for reception at multiple other stations.

15. The method of claim 14 wherein the information is further sufficient for another station to form a transmission that matches the first relationship.

16. The method of claim 14 wherein the information is further sufficient for another station to form a transmission that is substantially cancelled at the multiple antenna of the first station.

17. (canceled)

18. (canceled)

19. A communication method comprising:

monitoring transmissions over a medium at a first multiple antenna station, including monitoring transmissions from one or more other stations;

determining at the first station, for each of the one or more other stations receiving one or more transmissions on a medium, a first relationship between signals transmitted via the antennas of the first station such that the transmission from the first station avoids interference at the other stations with the one or more transmissions directed to said other stations; and

communication over the medium according the determined first relationship concurrently with the one or more transmissions.

20. The method of claim 19 wherein monitoring the transmissions over the medium includes receiving from at least one or said other stations information used to determine the first relationship between the signals transmitted.

21. The method of claim 19 wherein communicating over the medium includes matching a relationship of signals received at another station from a transmission not directed to said other station.

22. The method of claim 19 wherein communicating over the medium includes cancelling a transmission from the station at another station.

23. The method of claim 19 wherein determining the relationship comprises:

using information about ongoing transmissions and their receivers'"'"' status determines how to at least one of null and align its signal at the receivers of the ongoing transmissions such that it does not interfere with their reception of wanted signals;

using information about the ongoing transmissions and their receivers'"'"' status, determining a number of independent signals or degrees of freedom that the first can deliver to its own intended receivers; and

using information about the ongoing transmissions and their receivers'"'"' status pre-coding signals for transmission to avoid interfering with the reception of ongoing transmission at their corresponding receiver while enabling decodable reception at one or more intended receivers of the transmission.

24. (canceled)

25. (canceled)

26. A communication method comprising:

determining an indicator representing a data rates suitable for reception at a multiple antenna station in a transmission matching a first relationship between signals received at the multiple antennas; and

sending information over the medium from the station to another station encoding said indicator.

27. The method of claim 26 further comprising:

determining the first relationship between signals as suitable for reception of an information bearing transmission at multiple antennas of a station concurrently with one or more transmissions; and

wherein sending the information includes sending information sufficient for another multiple antenna system to form a transmission that matches the first relationship.

28. The method of claim 26 further comprising:

receiving from the other station a transmission characterizing the first relationship.

29. (canceled)

30. (canceled)