DYNAMIC ADJUSTMENT OF DOWNLINK/UPLINK ALLOCATION RATIO IN TDD WIRELESS SYSTEMS

• US 20090201838A1
• Filed: 02/06/2009
• Published: 08/13/2009
• Est. Priority Date: 02/08/2008
• Status: Active Grant

• Current Assignee: Advanced Standard Communication LLC
• Original Assignee: ZTE Corporation
• Inventors: Fang, Yonggang, Zhang, Wenfeng
• Granted Patent: US 8,233,413 B2
• Time in Patent Office: Days
• US Class Current: 370/280
• CPC Class Codes: H04B 7/2656 for structure of frame, burst
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04W 56/003 Arrangements to increase tolerance to errors in transmission or reception timing
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/1263 Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows
• CPC Class Codes: H04W 72/53 based on regulatory allocation policies

Abstract

Techniques, apparatuses, and systems for dynamically changing downlink and uplink allocations can include operating a base station under time division duplexing to communicate with one or more mobile devices using a frame structure, adjusting a downlink-uplink ratio to change an allocation between uplink and downlink data capacities in the frame structure, determining a mute interval based on the adjusted downlink-uplink ratio, generating mute information based on the mute interval to identify the one or more areas of the frame structure effected by the allocation change, and transmitting the mute information to the one or more mobile devices.

Claims

1. A method for dynamically changing a downlink-uplink allocation, comprising:

establishing a communication link between a base station and a user equipment, wherein the communication link comprises downlink intervals for the base station to transmit to the user equipment and uplink intervals for the user equipment to transmit to the base station; and

generating a mute interval to replace a downlink interval or an uplink interval in a previous frame to effect a change in a downlink-uplink allocation ratio for a subsequent frame; and

transmitting a location of the mute interval to the user equipment using a frame structure.

2. The method of claim 1, wherein the frame structure includes a slot-TDD frame structure, wherein the mute interval corresponds to one or more slots within the subsequent frame, and the mute interval indicates that transmissions during the mute interval should cease.

3. The method of claim 1, wherein the frame structure includes a symbol-TDD frame structure, wherein the mute interval corresponds to one or more mute symbols within the subsequent frame, and the mute interval indicates that transmissions during the mute interval should cease.

4. The method of claim 3, wherein the mute symbols are contiguous and the mute interval is adjacent to a guard period within the subsequent frame.

5. The method of claim 1, further comprising:

generating a data structure to specify the location of the mute interval, wherein the data structure is one of a bit mask data structure, a list data structure, a symbol set data structure, or a pre-defined allocation table entry structure, wherein transmitting the location comprises transmitting the data structure.

6. The method of claim 1, wherein generating the mute interval comprises generating information to indicate a presence of a mute slot in a specific slot of the frame structure, wherein the mute interval comprises the mute slot.

7. The method of claim 6, further comprising:

changing a downlink slot in the frame structure to the mute slot; and

operating the base station to either complete or immediately stop data transmission in the mute slot.

8. The method of claim 7, further comprising:

changing the mute slot to an uplink slot; and

controlling the user equipment to transmit in the uplink slot.

9. The method of claim 6, further comprising:

changing an uplink slot in the frame structure to the mute slot; and

operating the user equipment to either complete or immediately stop data transmission in the mute slot.

10. The method of claim 9, further comprising:

changing the mute slot to a downlink slot; and

operating the base station to transmit in the downlink slot.

11. The method of claim 1, wherein generating the mute interval comprises generating information to indicate a presence of a mute symbol in a specific symbol of the frame structure, wherein the mute interval comprises the mute symbol.

12. The method of claim 11, further comprising:

changing a downlink symbol in the frame structure to the mute symbol; and

operating the base station to either complete or immediately stop data transmission in the mute symbol.

13. The method of claim 12, further comprising:

changing the mute symbol to an uplink symbol; and

controlling the user equipment to transmit in the uplink symbol.

14. The method of claim 11, further comprising:

changing an uplink symbol in the frame structure to the mute symbol; and

operating the user equipment to either complete or immediately stop data transmission in the mute symbol.

15. The method of claim 14, further comprising:

changing the mute symbol to a downlink symbol; and

operating the base station to transmit in the downlink symbol.

16. The method of claim 1, wherein generating the mute interval comprises generating a bit-mask data structure to identify one or more slots in the frame structure effected by a muting operation.

17. The method of claim 1, wherein generating the mute interval comprises generating a list data structure to identify one or more slots of the frame structure effected by a muting operation.

18. The method of claim 1, wherein generating the mute interval comprises generating a set data structure to identify one or more symbols of the frame structure effected by a muting operation.

19. The method of claim 1, wherein generating the mute interval comprises generating one or more pre-defined allocation table entries to identify one or more areas of the frame structure effected by a muting operation.

20. The method of claim 1, further comprising:

operating a core network to send a mute request to the base station to initiate the change in the downlink-uplink allocation ratio;

operating the base station to send a mute response to the core network; and

operating the core network to send a mute recovery request to the base station.

21. The method in claim 20, wherein the mute request includes the information indicative of specific intervals to be muted in the frame structure.

22. The method in claim 21, wherein the mute request includes one of the following data structures defining one or more specific intervals in the frame structure:

a bit mask data structure, a list data structure, a set data structure, and pre-defined allocation table entries.

23. The method in claim 20, wherein the mute response is sent from the base station after the base station has no communication activities in the mute interval.

24. The method in claim 20, wherein the mute recovery request includes information indicative of a specific current mute interval of the frame structure that is to be changed to either a downlink interval or an uplink interval.

25. The method in claim 24, wherein the mute recovery request includes one of the following data structures defining specific intervals in the frame structure:

a bit mask data structure, a list data structure, a set data structure and pre-defined allocation table entries.

26. The method in claim 20, further comprising:

operating the base station to send a mute recovery confirmation to the core network, wherein the mute recovery confirmation is sent from base station after the base station resumes usage of the specific mute intervals of the frame structure for either uplink or downlink transmissions.

27. A method for wireless communications comprising:

operating a base station under time division duplexing to communicate with one or more mobile devices using a frame structure;

adjusting a downlink-uplink ratio to change an allocation between uplink and downlink data capacities in the frame structure;

determining a mute interval based on the adjusted downlink-uplink ratio, the mute interval comprising one or more areas of the frame structure;

generating mute information based on the mute interval to identify the one or more areas of the frame structure effected by the allocation change; and

transmitting the mute information to the one or more mobile devices.

28. The method of claim 27, wherein determining the mute interval comprises selecting an uplink or downlink interval within the frame structure as the mute interval.

29. The method of claim 28, further comprising:

controlling data transmission within the mute interval to complete or immediately stop.

30. The method of claim 29, further comprising:

changing the mute interval into an uplink or downlink interval according to the adjusted downlink-uplink ratio; and

scheduling one or more data transmissions for the changed mute interval.

31. The method of claim 27, wherein the mute interval comprises one or more slots in the frame structure.

32. The method of claim 27, wherein the mute interval comprises one or more symbols in the frame structure.

33. The method of claim 27, further comprising:

determining a plurality of adjustment values to iteratively change a current downlink-uplink ratio to a target downlink-uplink ratio, wherein adjusting the downlink-uplink ratio comprises using one of the adjustment values.

34. The method of claim 27, further comprising:

operating an additional base station under time division duplexing to communicate with one or more mobile devices; and

maintaining a downlink-uplink ratio for the additional base station separately from the adjusted downlink-uplink ratio.

35. A method of operating a device comprising:

using time division duplexing to communicate with a base station using a frame structure and a first allocation, wherein the frame structure comprises uplink and downlink data areas;

wherein the first allocation comprises a total size of the uplink area and a total size of the downlink area;

receiving muting information from the base station indicative of muting activity for a specific area of the frame structure, and indicative of a second allocation that differs from the first allocation;

completing operations associated with the specific area under the first allocation; and

commencing operations using the second allocation.

36. The method of claim 35, wherein completing operations comprises stopping a data transmission in the specific area.

37. The method of claim 36, wherein commencing operations using the second allocation comprises receiving data in the specific area.

38. The method of claim 35, wherein commencing operations using the second allocation comprises transmitting data in the specific area.

39. The method of claim 35, wherein the specific area comprises one or more slots.

40. The method of claim 35, wherein the specific area comprises one or more symbols.

41. The method of claim 35, wherein the specific area comprises nonadjacent areas in the frame structure.

42. An apparatus comprising:

a transceiver to communicate with one or more mobile devices using a frame structure under time division duplexing; and

a processing unit, in communication with the transceiver, configured to perform operations comprising;

adjusting a downlink-uplink ratio to change an allocation between uplink and downlink data capacities in the frame structure;

determining a mute interval based on the adjusted downlink-uplink ratio, the mute interval comprising one or more areas of the frame structure;

generating mute information based on the mute interval to identify the one or more areas of the frame structure effected by the allocation change; and

transmitting the mute information to the one or more mobile devices.

43. The apparatus of claim 42, wherein determining the mute interval comprises selecting an uplink or downlink interval within the frame structure as the mute interval.

44. The apparatus of claim 43, wherein the operations further comprises:

controlling data transmission within the mute interval to complete or immediately stop.

45. The apparatus of claim 44, wherein the operations further comprises:

changing the mute interval into an uplink or downlink interval according to the adjusted downlink-uplink ratio; and

scheduling one or more data transmissions for the changed mute interval.

46. The apparatus of claim 42, wherein the mute interval comprises one or more slots in the frame structure.

47. The apparatus of claim 42, wherein the mute interval comprises one or more symbols in the frame structure.

48. The apparatus of claim 42, wherein the operations further comprises:

determining a plurality of adjustment values to iteratively change a current downlink-uplink ratio to a target downlink-uplink ratio, wherein adjusting the downlink-uplink ratio comprises using one of the adjustment values.

49. The apparatus of claim 42, further comprising:

operating an additional base station under time division duplexing to communicate with one or more mobile devices; and

maintaining a downlink-uplink ratio for the additional base station separately from the adjusted downlink-uplink ratio.

50. An apparatus comprising:

a transceiver to communicate with a base station; and

a processing unit, in communication with the transceiver, configured to perform operations comprising;

using time division duplexing to communicate with the base station using a frame structure and a first allocation, wherein the frame structure comprises uplink and downlink data areas;

wherein the first allocation comprises a total size of the uplink area and a total size of the downlink area;

receiving muting information from the base station indicative of muting activity for a specific area of the frame structure, and indicative of a second allocation that differs from the first allocation;

completing operations associated with the specific area under the first allocation; and

commencing operations using the second allocation.

51. The apparatus of claim 50, wherein the specific area comprises one or more slots.

52. The apparatus of claim 50, wherein the specific area comprises one or more symbols.

53. A system for wireless communications comprising:

a controller configured to perform operations comprising;

adjusting a downlink-uplink ratio to change an allocation between uplink and downlink data capacities in a frame structure;

determining a mute interval based on the adjusted downlink-uplink ratio, the mute interval comprising one or more areas of the frame structure;

generating mute information based on the mute interval to identify the one or more areas of the frame structure effected by the allocation change; and

a base station, in communication with the controller, to communicate with one or more mobile devices using the frame structure under time division duplexing, wherein the base station is configured to transmit data including the mute information to the one or more mobile devices.

54. The system of claim 53, wherein determining the mute interval comprises selecting an uplink or downlink interval within the frame structure as the mute interval.

55. The system of claim 54, wherein the controller is further configured to perform operations comprising controlling data transmission within the mute interval to complete or immediately stop.

56. The system of claim 55, wherein the controller is further configured to perform operations comprising:

changing the mute interval into an uplink or downlink interval according to the adjusted downlink-uplink ratio; and

scheduling one or more data transmissions for the changed mute interval.

57. The system of claim 53, wherein the mute interval comprises one or more slots in the frame structure.

58. The system of claim 53, wherein the mute interval comprises one or more symbols in the frame structure.

59. The system of claim 53, wherein the controller is further configured to perform operations comprising:

determining a plurality of adjustment values to iteratively change a current downlink-uplink ratio to a target downlink-uplink ratio, wherein adjusting the downlink-uplink ratio comprises using one of the adjustment values.

60. The system of claim 53, further comprising:

an additional base station to communicate with one or more mobile devices, wherein the controller is further configured to perform operations comprising;

maintaining a downlink-uplink ratio for the additional base station separately from the adjusted downlink-uplink ratio.