Adaptive MIMO architecture

• US 20050181739A1
• Filed: 01/28/2005
• Published: 08/18/2005
• Est. Priority Date: 02/13/2004
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Krasny, Leonid, Molnar, Karl, Wang, Yi-Pin Eric, Grant, Stephen, Cheng, Jung-Fu Thomas
• Granted Patent: US 8,515,435 B2
• Time in Patent Office: Days
• US Class Current: 455/69
• CPC Class Codes: H04B 2201/709727 GRAKE type RAKE receivers
• CPC Class Codes: H04B 7/061 using feedback from receiving side
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/065 Variable contents, e.g. long-term or short-short
• CPC Class Codes: H04B 7/0686 Hybrid systems, i.e. switching and simultaneous transmission
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/003 Adaptive formatting arrangements particular to signalling, e.g. variable amount of bits
• CPC Class Codes: H04L 1/06 using space diversity

Abstract

An adaptive transmission scheme provides multiple levels of adaptation. At a first level, a selection is made between a limited feedback or open loop scheme and a rich feedback or closed loop scheme. At a second level of adaptation, a diversity mode is selected. Additional levels of adaptation could be employed.

Claims

1. A method of transmitting signals between a base station and a mobile station in a wireless communication network, the method comprising:

selecting a desired feedback mode to be one of a rich feedback mode and a limited feedback mode based on an expected performance at a mobile station; and

configuring a base station transmitter based on the desired feedback mode.

2. The method of claim 1 wherein selection of a desired feedback mode is based at least in part on mobile station capability.

3. The method of claim 1 wherein selection of a desired feedback mode is based at least in part on mobile station speed or velocity.

4. The method of claim 1 wherein selection of a desired feedback mode is based at least in part on available bandwidth between the mobile station and the base station.

5. The method of claim 1 wherein selection of a desired feedback mode is based at least in part on past performance of the mobile station in said rich feedback and limited feedback modes.

6. The method of claim 1 wherein selection of a desired feedback mode is based at least in part on characteristics of the communication channel between the base station an the mobile station.

7. The method of claim 1 wherein configuring a base station transmitter based on the desired feedback mode comprises configuring the base station transmitter to use per antenna rate control if the limited feedback mode is selected.

8. The method of claim 7 further comprising selecting a diversity mode and configuring the base station transmitter for the selected diversity mode.

9. The method of claim 8 wherein selecting a diversity mode comprises selecting a number of transmit antennas to use for transmission to said mobile station.

10. The method of claim 9 wherein selecting the diversity mode further comprises selecting a subset of a set of transmit antennas to use for transmission to the mobile station, wherein configuring the base station transmitter for the selected diversity mode comprises configuring the base station transmitter to use the selected antennas.

11. The method of claim 9 further comprising receiving an antenna selection from the mobile station indicating a subset of antennas to use for transmission to the mobile station, wherein configuring the base station transmitter for the selected diversity mode comprises configuring the base station transmitter to use the selected antennas.

12. The method of claim 7 further comprising receiving from the mobile station a diversity mode signal indicating a selected diversity mode and configuring the base station transmitter for the selected diversity mode.

13. The method of claim 12 further comprising receiving an antenna selection from the mobile station indicating a subset of selected antennas to use for transmission to the mobile station, wherein configuring the base station transmitter for the selected diversity mode comprises configuring the base station transmitter to use the selected antennas.

14. The method of claim 1 wherein configuring a base station transmitter based on the desired feedback mode comprises configuring the base station transmitter to use a spatial multiplexing coding scheme if the limited feedback mode is selected.

15. The method of claim 14 further comprising selecting a diversity mode and configuring the base station transmitter for the selected diversity mode.

16. The method of claim 15 wherein selecting a diversity mode comprises selecting a number of transmit antennas to use for transmission to said mobile station.

17. The method of claim 16 wherein selecting the diversity mode further comprises selecting a subset of a set of transmit antennas to use for transmission to the mobile station, wherein configuring the base station transmitter for the selected diversity mode comprises configuring the base station transmitter to use the selected antennas.

18. The method of claim 16 further comprising receiving an antenna selection from the mobile station indicating a subset of antennas to use for transmission to the mobile station, wherein configuring the base station transmitter for the selected diversity mode comprises configuring the base station transmitter to use the selected antennas.

19. The method of claim 14 further comprising receiving from the mobile station a diversity mode signal indicating a selected diversity mode and configuring the base station transmitter for the selected diversity mode.

20. The method of claim 19 further comprising receiving an antennas selection from the mobile station indicating a subset of selected antennas to use for transmission to the mobile station, wherein configuring the base station transmitter for the selected diversity mode comprises configuring the base station transmitter to use the selected antennas.

21. The method of claim 1 wherein configuring a base station transmitter based on the desired feedback mode comprises configuring the base station transmitter to use matched field processing transmit diversity if rich feedback mode is selected.

22. The method of claim 21 further comprising selecting a diversity mode based on channel information feedback from the mobile station and configuring the base station transmitter for the selected diversity mode.

23. The method of claim 22 wherein selecting a diversity mode comprises selecting a number of data streams to transmit to the mobile station based on said channel information feedback.

24. The method of claim 23 wherein said channel information feedback includes channel coefficients for one or more propagation channels from the base station transmitter to the mobile station.

25. The method of claim 24 wherein configuring the base station transmitter includes configuring a prefilter for each data stream based on said channel coefficients.

26. The method of claim 25 wherein each prefilter is configured to match a propagation channel from all transmit antennas to a selected receive antenna at the mobile station.

27. The method of claim 21 further comprising receiving a diversity mode selection from the mobile station indicating a selected diversity mode and configuring the base station transmitter for the selected diversity mode.

28. The method of claim 27 wherein the diversity mode selection indicates the number of data streams to transmit to the mobile station, and wherein configuring the base station transmitter includes configuring a prefilter for each data stream.

29. The method of claim 28 wherein each prefilter is configured to match a propagation channel from one or more selected transmit antennas to a selected receive antenna at the mobile station.

30. A base station comprising:

a transmitter having a plurality of transmit antennas; and

a transmission control circuit operatively coupled to the transmitter for selecting a desired feedback mode to be one of a rich feedback mode and a limited feedback mode, and for configuring said transmitter based on the desired feedback mode.

31. The base station of claim 30 wherein the transmission control circuit selects a desired feedback mode based at least in part on mobile station capability.

32. The base station of claim 30 wherein the transmission control circuit selects a desired feedback mode based at least in part on mobile station speed or velocity.

33. The base station of claim 30 wherein the transmission control circuit selects a desired feedback mode based at least in part on past performance of the mobile station in said rich feedback and limited feedback modes.

34. The base station of claim 30 wherein the transmission control circuit selects a desired feedback mode based at least in part on characteristics of the communication channel between the base station an the mobile station.

35. The base station of claim 30 wherein the transmission control circuit configures the transmitter to use per antenna rate control if the limited feedback mode is selected.

36. The base station of claim 35 wherein the transmission control circuit further selects a diversity mode and configures the base station transmitter for the selected diversity mode.

37. The base station of claim 36 wherein the transmission control circuit selects a diversity mode by selecting a number of transmit antennas to use for transmission to said mobile station.

38. The base station of claim 37 wherein the transmission control circuit selects a diversity mode by selecting a subset of a set of transmit antennas to use for transmission to the mobile station, wherein the transmission control circuit configures the transmitter to use the selected antennas.

39. The base station of claim 36 further comprising a receiver to receive an antenna selection from the mobile station indicating a subset of selected antennas to use for transmission to the mobile station, wherein the transmission control circuit configures the transmitter to use the selected antennas.

40. The base station of claim 35 further comprising a receiver to receive a diversity mode selection from a mobile station indicating a selected diversity mode, wherein the transmission control circuit configures the transmitter for the selected diversity mode responsive to receipt of the diversity mode selection from the mobile station.

41. The base station of claim 40 within the receiver receives an antenna selection indicating a subset of selected antennas to use for transmission to the mobile station, wherein the transmission control circuit configures the transmitter to use the selected antennas responsive to receipt of the antenna selection from the mobile station.

42. The base station of claim 30 wherein the transmission control circuit configures the transmitter to use a spatial multiplexing coding scheme if the limited feedback mode is selected.

43. The base station of claim 42 wherein the transmission control circuit further selects a diversity mode and configures the base station transmitter for the selected diversity mode.

44. The base station of claim 43 wherein the transmission control circuit selects a diversity mode by selecting a number of transmit antennas to use for transmission to said mobile station.

45. The base station of claim 44 wherein the transmission control circuit selects a diversity mode by selecting a subset of a set of transmit antennas to use for transmission to the mobile station, wherein the transmission control circuit configures the transmitter to use the selected antennas.

46. The base station of claim 43 further comprising a receiver to receive an antenna selection from the mobile station indicating a subset of selected antennas to use for transmission to the mobile station, wherein the transmission control circuit configures the transmitter to use the selected antennas.

47. The base station of claim 42 further comprising a receiver to receive a diversity mode selection from a mobile station indicating a selected diversity mode, wherein the transmission control circuit configures the transmitter for the selected diversity mode responsive to receipt of the diversity mode selection from the mobile station.

48. The base station of claim 47 within the receiver receives an antenna selection indicating a subset of selected antennas to use for transmission to the mobile station, wherein the transmission control circuit configures the transmitter to use the selected antennas responsive to receipt of the antenna selection from the mobile station.

49. The base station of claim 30 wherein the transmission control circuit configures the transmitter to use matched field processing transmit diversity if rich feedback mode is selected.

50. The base station of claim 49 wherein the transmission control circuit selects a diversity mode based on channel information feedback from the mobile station and configures the base station transmitter for the selected diversity mode.

51. The base station of claim 50 wherein the transmission control circuit selects a diversity mode by selecting a number of data streams to transmit to the mobile station based on said channel information feedback.

52. The base station of claim 51 wherein said channel information feedback includes channel coefficients for one or more propagation channels from the transmitter to the mobile station.

53. The base station of claim 51 wherein the transmission control circuit configures the transmitter by configuring a prefilter for each data stream based on said channel information feedback.

54. The base station of claim 53 wherein the transmission control circuit configures each prefilter to match a propagation channel from all transmit antennas to a selected receive antenna at the mobile station.

55. The base station of claim 49 further comprising a receiver to receive a diversity mode selection from the mobile station indicating a selected diversity mode, wherein the transmission control circuit configures the station transmitter for the selected diversity mode responsive to receipt of a diversity mode selection from the mobile station.

56. The base station of claim 55 wherein the diversity mode selection indicates the number of data streams to transmit to the mobile station, and wherein configuring the base station transmitter includes configuring a prefilter for each data stream.

57. The base station of claim 56 wherein each prefilter is configured to match the channel to a selected receive antenna at the mobile station.