Cooperative MIMO in multicell wireless networks

• US 20060120477A1
• Filed: 12/07/2004
• Published: 06/08/2006
• Est. Priority Date: 12/07/2004
• Status: Active Grant

• Current Assignee: Adaptix, Inc. (Acacia Research Corporation)
• Original Assignee: Adaptix, Inc. (Acacia Research Corporation)
• Inventors: Liu, Hui, Xing, Guanbin, Shen, Manyuan
• Granted Patent: US 7,428,268 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/068 using space frequency diversity space-frequency coding H04L1/0606
• CPC Class Codes: H04L 1/0625 Transmitter arrangements
• CPC Class Codes: H04L 2001/0092 Error control systems characterised by the topology of the transmission link
• CPC Class Codes: H04L 27/2626 Arrangements specific to the transmitter only

Abstract

A method and system for cooperative multiple-input multiple output (MIMO) transmission operations in a multicell wireless network. Under the method, antenna elements from two or more base stations are used to from an augmented MIMO antenna array that is used to transmit and receive MIMO transmissions to and from one or more terminals. The cooperative MIMO transmission scheme supports higher dimension space-time-frequency processing for increased capacity and system performance.

Claims

1. A method comprising:

employing antenna elements from a plurality of base stations to support cooperative multiple-input multiple-output (MIMO) transmissions in a wireless network.

2. The method of claim 1, wherein the cooperative MIMO transmissions comprise orthogonal frequency division multiple access (OFDMA) MIMO transmissions.

3. The method of claim 1, further comprising encoding the cooperative MIMO transmissions using space-time coding.

4. The method of claim 3, wherein the space-time coding comprises space-time trellis coding.

5. The method of claim 3, wherein the space-time coding comprises space-time block coding.

6. The method of claim 3, further comprising encoding the cooperative MIMO transmissions using space-time coding with delay diversity.

7. The method of claim 1, further comprising encoding the cooperative MIMO transmissions using space-frequency coding.

8. The method of claim 1, further comprising encoding the cooperative MIMO transmissions using space-time-frequency coding.

9. The method of claim 1, further comprising performing spatial multiplexing on the cooperative MIMO transmissions.

10. The method of claim 1, wherein the cooperative MIMO transmissions include downlink transmissions from the plurality of base stations to terminals and uplink transmissions from the terminals to the plurality of base stations.

11. The method of claim 1, further comprising performing spatial beamforming for selected MIMO transmissions.

12. The method of claim 11, further comprising performing spatial beamforming in combination with one of space-time, space-frequency and space-time-frequency coding of the selected MIMO transmissions.

13. The method of claim 1, further comprising transmitting a cooperative MIMO transmission to at least two terminals simultaneously.

14. The method of claim 13, further comprising performing spatial beamforming on the cooperative MIMO transmissions such that MIMO transmissions are directed toward intended users while spatial nulling is effected toward unintended users.

15. The method of claim 1, further comprising jointly decoding uplink MIMO transmissions received from multiple terminals.

16. The method of claim 1, further comprising jointly decoding downlink MIMO transmissions received at multiple terminals.

17. The method of claim 1, further comprising separately decoding uplink MIMO transmissions received from multiple terminals.

18. The method of claim 1, further comprising jointly encoding downlink MIMO transmissions sent to multiple terminals.

19. The method of claim 18, further comprising:

decoding a jointly encoded downlink MIMO transmission at a terminal; and

keeping portions of data sent via jointly encoded downlink MIMO transmission intended for the terminal, while discarding other portions of data that are not intended for the terminal.

20. The method of claim 18, further comprising separately decoding the jointly encoded downlink transmissions at each of the multiple terminals.

21. The method of claim 1, further comprising:

generating antenna drive signals via at a first facility;

sending respective portions of the antenna drive signals to each of the base stations; and

performing cooperative MIMO transmissions by driving selected antenna elements at the base stations with the respective portion of the antenna drive signals sent to those base stations.

22. The method of claim 21, wherein the first facility is co-located with one of the base stations.

23. The method of claim 21, further comprising synchronizing transmission of the respective portions of antenna drive signals sent to the base stations.

24. The method of claim 1, further comprising:

replicating a data stream received from an information source;

forwarding a replication of the data stream to each base station;

performing antenna signal processing operations at each base station on the data stream it receives to generate antenna signals; and

transmitting the antenna signals over selected antenna elements at each of the base station to form a cooperative MIMO transmission.

25. The method of claim 24, further comprising synchronizing performing the antenna signal processing operations at the base stations such that the generated antenna signals are transmitted over the selected antenna elements at different base stations in synchrony.

26. The method of claim 1, further comprising performing cooperative MIMO transmissions to facilitate terminal handoff between wireless network cells or sectors.

27. The method of claim 1, further comprising:

performing MIMO encoding on a data stream to be transmitted over a corresponding cooperative MIMO channel, the MIMO encoding producing respective sets of encoded data sequences on which antenna signal processing is to be performed at respective base stations;

sending each respective set of encoded data sequences to its corresponding base station; and

performing antenna signal processing operations to generate antenna signals at each of the base stations in view of the set of encoded data sequences received by that base station; and

transmitting the antenna signals over corresponding antenna elements at each of the base station to transmit the data stream over the cooperative MIMO channel.

28. The method of claim 27, further comprising synchronizing performing the antenna signal processing operations at the base stations such that the generated antenna signals are transmitted over the selected antenna elements at different base stations in synchrony.

29. A multicell wireless network, comprising:

a plurality of base stations, each associated with a respective cell and having a respective antenna array including at least one antenna element; and

a cooperative multiple-input multiple-output (MIMO) transmission mechanism that employs selected antenna elements from the plurality of base stations to form an augmented antenna array used to support cooperative MIMO transmissions over the wireless network.

30. The multicell wireless network of claim 29, wherein the cooperative MIMO transmissions comprises orthogonal frequency division multiple access (OFDMA) MIMO transmissions.

31. The multicell wireless network of claim 29, wherein the cooperative MIMO transmission mechanism encodes the cooperative MIMO transmissions using space-time coding.

32. The multicell wireless network of claim 31, wherein the space-time coding comprises space-time trellis coding.

33. The multicell wireless network of claim 31, wherein the space-time coding comprises space-time block coding.

34. The multicell wireless network of claim 31, wherein the cooperative MIMO transmission mechanism encodes the cooperative MIMO transmissions using space-time coding with delay diversity.

35. The multicell wireless network of claim 29, wherein the cooperative MIMO transmission mechanism encodes the cooperative MIMO transmissions using space-frequency coding.

36. The multicell wireless network of claim 29, wherein the cooperative MIMO transmission mechanism encodes the cooperative MIMO transmissions using space-time-frequency coding.

37. The multicell wireless network of claim 29, wherein the cooperative MIMO transmission mechanism performs spatial multiplexing on the cooperative MIMO transmissions.

38. The multicell wireless network of claim 29, wherein the cooperative MIMO transmissions include downlink transmissions from the plurality of base stations to terminals and uplink transmissions from the terminals to the plurality of base stations.

39. The multicell wireless network of claim 29, wherein the cooperative MIMO transmission mechanism performs spatial beamforming for selected MIMO transmissions.

40. The multicell wireless network of claim 39, wherein the cooperative MIMO transmission mechanism performs spatial beamforming in combination with one of space-time, space-frequency and space-time-frequency coding of the selected MIMO transmissions.

41. The multicell wireless network of claim 29, wherein the cooperative MIMO transmission mechanism performs transmitting a cooperative MIMO transmission to at least two terminals simultaneously.

42. The multicell wireless network of claim 41, wherein the cooperative MIMO transmission mechanism further performs spatial beamforming on the cooperative MIMO transmissions such that MIMO transmissions are directed toward intended users while spatial nulling is effected toward unintended users.

43. The multicell wireless network of claim 29, wherein the cooperative MIMO transmission mechanism further performs jointly decoding uplink MIMO transmissions received from multiple terminals.

44. The multicell wireless network of claim 29, wherein the cooperative MIMO transmission mechanism further performs separately decoding uplink MIMO transmissions received from multiple terminals.

45. The multicell wireless network of claim 29, wherein the cooperative MIMO transmission mechanism further performs jointly encoding downlink MIMO transmissions sent to multiple terminals.

46. The multicell wireless network of claim 29, further comprising:

a cooperative MIMO master encoder to;

generate antenna drive signals; and

send respective portions of the antenna drive signals to each of the base stations;

wherein cooperative MIMO transmissions are performed by driving selected antenna elements at the base stations with the respective portion of the antenna drive signals sent to those base stations.

47. The multicell wireless network of claim 46, wherein the cooperative MIMO master encoder is co-located with one of the base stations.

48. The multicell wireless network of claim 46, further comprising a synchronizing mechanism to synchronize transmission of the respective portions of antenna drive signals sent to the base stations.

49. The multicell wireless network of claim 29, further comprising:

a data replicator to;

replicate a data stream received from an information source; and

forward a replication of the data stream to each base station; and

a set of antenna signal processing components at each base station to perform antenna signal processing operations on the data stream it receives to generate antenna signals,

wherein the antenna signals are transmitted over selected antenna elements at each of the base station to form a cooperative MIMO transmission.

50. The multicell wireless network of claim 49, further comprising a synchronizing mechanism to synchronize the antenna signal processing operations at the base stations such that the generated antenna signals are transmitted over the selected antenna elements at different base stations in synchrony.

51. The multicell wireless network of claim 29, further comprising:

a master encoder to;

perform MIMO encoding on a data stream to be transmitted over a corresponding cooperative MIMO channel, the MIMO encoding producing respective sets of encoded data sequences on which antenna signal processing is to be performed at respective base stations;

send each respective set of encoded data sequences to its corresponding base station; and

a set of antenna signal processing components at each base station to perform antenna signal processing operations on the set of encoded data sequences it receives to generate antenna signals,

wherein the antenna signals are transmitted over selected antenna elements at each of the base station to form a cooperative MIMO transmission over the cooperative MIMO channel.

52. The multicell wireless network of claim 51, further comprising a synchronizing mechanism to synchronize the antenna signal processing operations at the base stations such that the generated antenna signals are transmitted over the selected antenna elements at different base stations in synchrony.

53. The multicell wireless network of claim 29, wherein the cooperative MIMO transmission mechanism performs cooperative MIMO transmissions to facilitate terminal handoff between wireless network cells or sectors.