Method and system for multiple-input-multiple-output (MIMO) communication in a wireless network

• US 20070140208A1
• Filed: 06/23/2006
• Published: 06/21/2007
• Est. Priority Date: 12/15/2005
• Status: Active Grant

• Current Assignee: Sasken Communication Technologies Limited
• Original Assignee: Sasken Communication Technologies Limited
• Inventors: Varikat, Anubala
• Granted Patent: US 7,965,687 B2
• Time in Patent Office: Days
• US Class Current: 370/345
• CPC Class Codes: H04B 7/026 Co-operative diversity, e.g. using fixed or mobile stations as relays
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/0671 using different delays between antennas

Abstract

A method and a system for Multiple-Input-Multiple-Output (MIMO) communication in a wireless network are provided. According to the method, streams of the data of a user-equipment are communicated to a group of user-equipments that act as antennas for the user-equipment. The communication between the various user-equipments is through an Interlink. The data of the user-equipment is communicated with base stations by the user-equipment and the group of user-equipments in a single slot.

Claims

1. A method for uplink communication of data from a plurality of user-equipments to one or more base stations in a wireless network, the data belonging to a first user-equipment, the data being split and processed into one or more streams, the method comprising the steps of:

a. transmitting a first stream of the one or more streams by the first user-equipment to the one or more base stations in a slot, wherein the slot is assigned for uplink communication of the data of the first user-equipment;

b. transmitting the remaining streams of the one or more streams to a first set of user-equipments by the first user-equipment on an Interlink, the first set of user-equipments comprising one or more of the plurality of user-equipments that operate as antennas for the first user-equipment, the Interlink being an arrangement for communication between the plurality of user-equipments;

c. receiving the remaining streams of the one or more streams by the first set of user-equipments on the Interlink; and

d. transmitting the remaining streams of the one or more streams by the first set of user-equipments to the one or more base stations in the slot.

2. The method according to claim 1 further comprising the step of forming the first set of user-equipments by the one or more base stations.

3. The method according to claim 1 further comprising the step of forming the first set of user-equipments by the first user-equipment.

4. The method according to claim 1 further comprising the step of forming the first set of user-equipments by the first user-equipment and one or more of the plurality of user-equipments.

5. The method according to claim 4, wherein the step of forming the first set of user-equipments comprises the steps of:

a. defining a first maximum number of user-equipments that can be present in the first set of user-equipments;

b. ascertaining a first number of user-equipments, the first number being the number of user-equipments in the first set of user-equipments;

if the first number is less than the first maximum number,

i. receiving an indication of availability on the Interlink, the indication of availability being broadcast by a second user-equipment that can operate as an antenna for the first user-equipment;

ii. ascertaining channel conditions between the second user-equipment and the first user-equipment from a pilot signal received on the Interlink, the pilot signal being broadcast by the second user-equipment;

iii. adding the second user-equipment to the first set of user-equipments if the channel conditions meet a set of conditions; and

iv. sending a first notification to the second user-equipment, the first notification notifying the second user-equipment that the second user-equipment has been added in the first set of user-equipments.

6. The method according to claim 5, wherein the step of forming the first set of user-equipments further comprises the steps of:

if the indication of availability is not received on the Interlink,

a. sending a request to a third user-equipment to act as an antenna for the first user-equipment;

b. receiving an indication of availability from the third user-equipment;

c. ascertaining channel conditions between the third user-equipment and the first user-equipment from a pilot signal received on the Interlink, the pilot signal being broadcast by the third user-equipment;

d. adding the third user-equipment to the first set of user-equipments if the channel conditions meet a set of conditions; and

e. sending the first notification to the third user-equipment.

7. The method according to claim 4, wherein the step of forming the first set of user-equipments further comprises the steps of:

a. receiving a second notification from a fourth user-equipment, wherein the second notification notifying the first user-equipment that the fourth user-equipment is not operating as an antenna for the first user-equipment; and

b. removing the fourth user-equipment from the first set of user-equipments.

8. The method according to claim 1 further comprising the step of changing the first set of user-equipments based on one or more conditions.

9. The method according to claim 1 further comprising the step of forming a second set of user-equipments by the one or more base stations, the second set of user-equipments comprising one or more of the plurality of user-equipments for which the first user-equipment operates as an antenna.

10. The method according to claim 1 further comprising the step of forming a second set of user-equipments by the first user-equipment, the second set of user-equipments comprising one or more of the plurality of user-equipments for which the first user-equipment operates as an antenna.

11. The method according to claim 1 further comprising the step of forming a second set of user-equipments by the first user-equipment and one or more of the plurality of user-equipments, the second set of user-equipments comprising one or more of the plurality of user-equipments for which the first user-equipment operates as an antenna.

12. The method according to claim 11, wherein the step of forming the second set of user-equipments comprises the steps of:

a. defining a second maximum number of user-equipments that can be present in the second set of user-equipments;

b. ascertaining a second number of user-equipments, wherein the second number is the number of user-equipments in the second set of user-equipments;

if the second number is less than the second maximum number,

i. sending an indication of availability on the Interlink, the indication of availability notifying that the first user-equipment can operate as an antenna;

ii. receiving a first notification from a fifth user-equipment, the first notification notifying the first user-equipment to add the fifth user-equipment in the second set of user-equipments; and

iii. adding the fifth user-equipment in the second set of user-equipments.

13. The method according to claim 12, wherein the step of forming the second set of user-equipments further comprises the steps of:

a. receiving a request from a sixth user-equipment to add the sixth user-equipment in the second set of user-equipments;

if the second number is equal to the second maximum number,

i. removing a seventh user-equipment from the second set of user-equipments;

ii. sending an indication of availability to the sixth user-equipment;

iii. receiving the first notification from the sixth user-equipment; and

iv. sending a second notification to the seventh user-equipment, the second notification notifying the seventh user-equipment that the seventh user-equipment has been removed from the second set of user-equipments.

14. The method according to claim 1 further comprising the step of changing a second set of user-equipments based on one or more channel conditions, the second set of user-equipments comprising one or more of the plurality of user-equipments for which the first user-equipment operates as an antenna.

15. The method of claim 1 for uplink communication of data from a plurality of user-equipments to one or more base stations in a wireless network, the data belonging to a first user-equipment, the data being split and processed into one or more streams, the method being performed by a data processor according to computer-executable instructions stored on a computer-readable medium.

16. A method for downlink communication of data from one or more base stations to a plurality of user-equipments in a wireless network, each base station comprising one or more antennas, the data belonging to a first user-equipment, the data being split and processed into one or more streams based on the one or more antennas, the method comprising the steps of:

a. transmitting the data from the one or more antennas of the one or more base stations in a slot, the slot being assigned for downlink communication of the data of the first user-equipment;

b. receiving the data by the first user-equipment in the slot;

c. receiving the data by a first set of user-equipments in the slot, the first set of user-equipments comprising one or more of the plurality user-equipments that operate as antennas for the first user-equipment;

d. transmitting the data by the first set of user-equipments to the first user-equipment on an Interlink, the Interlink being a scheme for communication between the plurality of user-equipments;

e. receiving the data from the first set of user-equipments by the first user-equipment; and

f. combining and decoding the data received from the one or more base stations and the data received from the first set of user-equipments by the first user-equipment.

17. The method according to claim 16 further comprising the step of controlling power transmitted to the first user-equipment based on the number of user-equipments in the first set and on the channel strengths between them.

18. The method according to claim 16 further comprising the step of forming the first set of user-equipments by the one or more base stations.

19. The method according to claim 16 further comprising the step of forming the first set of user-equipments by the first user-equipment.

20. The method according to claim 16 further comprising the step of forming the first set of user-equipments by the first user-equipment and one or more of the plurality of user-equipments.

21. The method according to claim 20, wherein the step of forming the first set of user-equipments comprises the steps of:

a. defining a first maximum number of user-equipments that can be present in the first set of user-equipments;

b. ascertaining a first number of user-equipments, the first number being the number of user-equipments in the first set of user-equipments;

if the first number is less than the first maximum number,

i. receiving an indication of availability on the Interlink, the indication of availability being broadcast by a second user-equipment that can operate as an antenna for the first user-equipment;

ii. ascertaining channel conditions between the second user-equipment and the first user-equipment from a pilot signal received on the Interlink, the pilot signal being broadcast by the second user-equipment;

iii. adding the second user-equipment to the first set of user-equipments if the channel conditions meet a set of conditions; and

iv. sending a first notification to the second user-equipment, the first notification notifying the second user-equipment that the second user-equipment has been added in the first set of user-equipments.

22. The method according to claim 21, wherein the step of forming the first set of user-equipments further comprises the step of:

if the indication of availability is not received on the Interlink,

a. sending a request to a third user-equipment to act as an antenna for the first user-equipment;

b. receiving an indication of availability from the third user-equipment;

c. ascertaining channel conditions between the third user-equipment and the first user-equipment from a pilot signal received on the Interlink, the pilot signal being broadcast by the third user-equipment;

d. adding the third user-equipment to the first set of user-equipments if the channel conditions meet a set of conditions; and

e. sending the first notification to the third user-equipment.

23. The method according to claim 20, wherein the step of forming the first set of user-equipments further comprises the step of:

a. receiving a second notification from a fourth user-equipment, wherein the second notification notifying the first user-equipment that the fourth user-equipment is not operating as an antenna for the first user-equipment; and

b. removing the fourth user-equipment from the first set of user-equipments.

24. The method according to claim 16 further comprising the step of changing the first set of user-equipments based on one or more conditions.

25. The method according to claim 16 further comprising the step of forming a second set of user-equipments by the one or more base stations, the second set of user-equipments comprising one or more of the plurality of user-equipments for which the first user-equipment operates as an antenna.

26. The method according to claim 16 further comprising the step of forming a second set of user-equipments by the first user-equipment, the second set of user-equipments comprising one or more of the plurality of user-equipments for which the first user-equipment operates as an antenna.

27. The method according to claim 16 further comprising the step of forming a second set of user-equipments by the first user-equipment and one or more of the plurality of user-equipments, the second set of user-equipments comprising one or more of the plurality of user-equipments for which the first user-equipment operates as an antenna.

28. The method according to claim 27, wherein the step of forming the second set of user-equipments comprises the step of:

a. defining a second maximum number of user-equipments that can be present in the second set of user-equipments;

b. ascertaining a second number of user-equipments, wherein the second number is the number of user-equipments in the second set of user-equipments;

if the second number is less than the second maximum number,

i. sending an indication of availability on the Interlink, the indication of availability notifying that the first user-equipment can operate as an antenna;

ii. receiving a first notification from a fifth user-equipment, the first notification notifying the first user-equipment to add the fifth user-equipment in the second set of user-equipments; and

iii. adding the fifth user-equipment in the second set of user-equipments.

29. The method according to claim 28, wherein the step of forming the second set of user-equipments further comprises the steps of:

a. receiving a request from a sixth user-equipment to add the sixth user-equipment in the second set of user-equipments;

if the second number is equal to the second maximum number,

i. removing a seventh user-equipment from the second set of user-equipments;

ii. sending an indication of availability to the sixth user-equipment;

iii. receiving the first notification from the sixth user-equipment; and

iv. sending a second notification to the seventh user-equipment, the second notification notifying the seventh user-equipment that the seventh user-equipment has been removed from the second set of user-equipments.

30. The method according to claim 16 further comprising the step of changing a second set of user-equipments based on one or more channel conditions, the second set of user-equipments comprising one or more of the plurality of user-equipments for which the first user-equipment operates as an antenna.

31. The method of claim 16 for downlink communication of data from one or more base stations to a plurality of user-equipments in a wireless network, the data belonging to a first user-equipment, the data being split and processed into a number of streams based on the number of antennas of the one or more base stations, the method being performed by a data processor according to computer-executable instructions stored on a computer-readable medium.

32. A system for communication in a wireless network, the system comprising:

a. one or more base stations;

b. a plurality of user-equipments, the plurality of user-equipments communicating with each other and the one or more base stations; and

c. an Interlink, the Interlink facilitating the communication between the plurality of user-equipments.

33. The system according to claim 32 further comprising means for uplink communication of data from the plurality of user-equipments to the one or more base stations, the data belonging to a first user-equipment, the data being split and processed into one or more streams, the system comprising:

a. means for transmitting a first stream of the one or more streams by the first user-equipment to the one or more base stations in a slot, wherein the slot is assigned for uplink communication of the data of the first user-equipment;

b. means for transmitting the remaining streams of the one or more streams to the first set of user-equipments by the first user-equipment on an Interlink, the first set of user-equipments comprising one or more of the plurality of user-equipments that operate as antennas for the first user-equipment, the Interlink being a scheme for communication between the plurality of user-equipments;

c. means for receiving the remaining streams of the one or more streams by the first set of user-equipments on the Interlink; and

d. means for transmitting the remaining streams of the one or more streams by the first set of user-equipments to the one or more base stations in the slot.

34. The system according to claim 33 further comprising means for forming the first set of user-equipments.

35. The system according to claim 34, wherein means for forming the first set of user-equipments comprises:

a. means for defining a first maximum number of user-equipments that can be present in the first set of user-equipments;

b. means for ascertaining a first number of user-equipments, the first number being the number of user-equipments in the first set of user-equipments;

c. means for receiving an indication of availability on the Interlink, the indication of availability being broadcast by a second user-equipment that can operate as an antenna for the first user-equipment;

d. means for ascertaining channel conditions between the second user-equipment and the first user-equipment from a pilot signal received on the Interlink, the pilot signal being broadcast by the second user-equipment;

e. means for adding the second user-equipment to the first set of user-equipments if the channel conditions meet a set of conditions; and

f. means for sending a first notification to the second user-equipment, the first notification notifying the second user-equipment that the second user-equipment has been added in the first set of user-equipments.

36. The system according to claim 33 further comprising means for forming a second set of user-equipments, the second set of user-equipments comprising one or more of the plurality of user-equipments for which the first user-equipment operates as an antenna.

37. The system according to claim 36, wherein the means for forming the second set of user-equipments comprises:

a. means for defining a second maximum number of user-equipments that can be present in the second set of user-equipments;

b. means for ascertaining a second number of user-equipments, wherein the second number is the number of user-equipments in the second set of user-equipments;

c. means for sending an indication of availability on the Interlink, the indication of availability notifying that the first user-equipment can operate as an antenna;

d. means for receiving a first notification from a fifth user-equipment, the first notification notifying the first user-equipment to add the fifth user-equipment in the second set of user-equipments; and

e. means for adding the fifth user-equipment in the second set of user-equipments.

38. The system according to claim 32, further comprising means for downlink communication of data from the one or more base stations to the plurality of user-equipments in a wireless network, each base station comprising one or more antennas, the data belonging to a first user-equipment, the data being split and processed into one or more streams based on the one or more antennas, the system comprising:

a. means for transmitting the data from the one or more antennas of the one or more base stations in a slot, the slot being assigned for downlink communication of the data of the first user-equipment;

b. means for receiving the data by the first user-equipment in the slot;

c. means for receiving the data by a first set of user-equipments in the slot, the first set of user-equipments comprising one or more of the plurality user-equipments that operate as antennas for the first user-equipment;

d. means for transmitting the data by the first set of user-equipments to the first user-equipment on an Interlink, the Interlink being a scheme for communication between the plurality of user-equipments;

e. means for receiving the data from the first set of user-equipments by the first user-equipment; and

f. means for combining and decoding the data received from the one or more base stations and the data received from the first set of user-equipments by the first user-equipment.

39. The system according to claim 38 further comprising means for forming the first set of user-equipments.

40. The system according to claim 39, wherein the means for forming the first set of user-equipments comprises:

a. means for defining a first maximum number of user-equipments that can be present in the first set of user-equipments;

b. means for ascertaining a first number of user-equipments, the first number being the number of user-equipments in the first set of user-equipments;

c. means for receiving an indication of availability on the Interlink, the indication of availability being broadcast by a second user-equipment that can operate as an antenna for the first user-equipment;

d. means for ascertaining channel conditions between the second user-equipment and the first user-equipment from a pilot signal received on the Interlink, the pilot signal being broadcast by the second user-equipment;

e. means for adding the second user-equipment to the first set of user-equipments if the channel conditions meet a set of conditions; and

f. means for sending a first notification to the second user-equipment, the first notification notifying the second user-equipment that the second user-equipment has been added in the first set of user-equipments.

41. The system according to claim 38 further comprising means for forming a second set of user-equipments, the second set of user-equipments comprising one or more of the plurality of user-equipments for which the first user-equipment operates as an antenna.

42. The system according to claim 41, wherein the means for forming the second set of user-equipments comprises:

a. means for defining a second maximum number of user-equipments that can be present in the second set of user-equipments;

b. means for ascertaining a second number of user-equipments, wherein the second number is the number of user-equipments in the second set of user-equipments;

c. means for sending an indication of availability on the Interlink, the indication of availability notifying that the first user-equipment can operate as an antenna;

d. means for receiving a first notification from a fifth user-equipment, the first notification notifying the first user-equipment to add the fifth user-equipment in the second set of user-equipments; and

e. means for adding the fifth user-equipment in the second set of user-equipments.