TECHNIQUES FOR SUPPORTING RELAY OPERATION IN WIRELESS COMMUNICATION SYSTEMS

• US 20100080166A1
• Filed: 09/28/2009
• Published: 04/01/2010
• Est. Priority Date: 09/30/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Bhushan, Naga, Palanki, Ravi, Montojo, Juan, Ji, Tingfang, Khandekar, Aamod D., Bhattad, Kapil
• Granted Patent: US 9,294,219 B2
• Time in Patent Office: Days
• US Class Current: 370/315
• CPC Class Codes: H04B 7/15557 Selecting relay station operation mode, e.g. between amplify and forward mode, decode and forward mode or FDD - and TDD mode
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04J 3/08 Intermediate station arrangements, e.g. for branching, for tapping-off
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0023 characterised by the signalling
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04W 28/00 Network traffic management; Network resource management
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services

Abstract

Techniques for supporting operation of relay stations in wireless communication systems are described. In an aspect, a base station may transmit data to a relay station in a portion of a subframe instead of the entire subframe. The relay station may transmit control information during part of the subframe. The base station may transmit data to the relay station during the remaining part of the subframe. In another aspect, a target termination for a packet may be selected based on data and/or ACK transmission opportunities available for the packet. One or more transmissions of the packet may be sent with HARQ, and ACK information may be sent for the packet. The packet may be transmitted such that it can be terminated prior to the first subframe (i) not available for sending the packet or (ii) available for sending ACK information.

Claims

1. A method for wireless communication, comprising:

determining at a first station a target termination for a packet based on acknowledgement (ACK) transmission opportunities available to a second station for the packet;

selecting a modulation and coding scheme (MCS) for the packet based on the target termination for the packet; and

transmitting the packet in accordance with the selected MCS from the first station to the second station.

2. The method of claim 1, wherein ACK information for the packet can be sent in subframes of an interlace, and wherein the ACK transmission opportunities correspond to subframes belonging in the interlace and allocated for use.

3. The method of claim 1, wherein the target termination for the packet is determined based on a first ACK transmission opportunity for the packet.

4. The method of claim 1, wherein the target termination for the packet is K transmissions of the packet if K ACK transmission opportunities are available for the packet, where K is an integer greater than one.

5. The method of claim 1, wherein transmissions of the packet are sent at a first periodicity, and wherein subframes at a second periodicity are allocated for use, the second periodicity being different from the first periodicity.

6. The method of claim 5, wherein the first periodicity corresponds to 8 milliseconds (ms) and the second periodicity corresponds to 10 ms.

7. The method of claim 1, wherein the first station is a base station and the second station is a relay station.

8. The method of claim 1, wherein the first station is a relay station and the second station is a user equipment (UE).

9. An apparatus for wireless communication, comprising:

means for determining at a first station a target termination for a packet based on acknowledgement (ACK) transmission opportunities available to a second station for the packet;

means for selecting a modulation and coding scheme (MCS) for the packet based on the target termination for the packet; and

means for transmitting the packet in accordance with the selected MCS from the first station to the second station.

10. The apparatus of claim 9, wherein ACK information for the packet can be sent in subframes of an interlace, and wherein the ACK transmission opportunities correspond to subframes belonging in the interlace and allocated for use.

11. The apparatus of claim 9, wherein the target termination for the packet is determined based on a first ACK transmission opportunity for the packet.

12. The apparatus of claim 9, wherein the target termination for the packet is K transmissions of the packet if K ACK transmission opportunities are available for the packet, where K is an integer greater than one.

13. The apparatus of claim 9, wherein transmissions of the packet are sent at a first periodicity, and wherein subframes at a second periodicity are allocated for use, the second periodicity being different from the first periodicity.

14. An apparatus for wireless communication, comprising:

at least one processor configured to determine at a first station a target termination for a packet based on acknowledgement (ACK) transmission opportunities available to a second station for the packet, to select a modulation and coding scheme (MCS) for the packet based on the target termination for the packet, and to send the packet in accordance with the selected MCS from the first station to the second station.

15. The apparatus of claim 14, wherein ACK information for the packet can be sent in subframes of an interlace, and wherein the ACK transmission opportunities correspond to subframes belonging in the interlace and allocated for use.

16. The apparatus of claim 14, wherein the target termination for the packet is determined based on a first ACK transmission opportunity for the packet.

17. The apparatus of claim 14, wherein the target termination for the packet is K transmissions of the packet if K ACK transmission opportunities are available for the packet, where K is an integer greater than one.

18. The apparatus of claim 14, wherein transmissions of the packet are sent at a first periodicity, and wherein subframes at a second periodicity are allocated for use, the second periodicity being different from the first periodicity.

19. A computer program product, comprising:

a computer-readable medium comprising;

code for causing at least one computer to determine at a first station a target termination for a packet based on acknowledgement (ACK) transmission opportunities available to a second station for the packet,

code for causing the at least one computer to select a modulation and coding scheme (MCS) for the packet based on the target termination for the packet, and

code for causing the at least one computer to send the packet in accordance with the selected MCS from the first station to the second station.

20. A method for wireless communication, comprising:

determining a subframe to send data from a first station to a second station;

determining a part of the subframe used by the second station to transmit control information; and

transmitting data from the first station to the second station in remaining part of the subframe.

21. The method of claim 20, further comprising:

selecting a modulation and coding scheme (MCS) based on transmission of the data in only the remaining part of the subframe instead of an entire subframe; and

processing the data in accordance with the selected MCS.

22. The method of claim 20, wherein the subframe comprises a control portion and a data portion, wherein the data is transmitted in the entire data portion if the second station is not transmitting control information in the subframe and is transmitted in only part of the data portion if the second station is transmitting control information in the subframe.

23. The method of claim 20, wherein timing of the first station is offset by N symbol periods relative to timing of the second station, where N is one or greater.

24. The method of claim 23, wherein the offset of N symbol periods is selected to avoid overlapping of control information and reference signal sent by the first station with control information and reference signal sent by the second station.

25. The method of claim 20, wherein the first station is a base station and the second station is a relay station.

26. The method of claim 20, wherein the first station is a relay station and the second station is a base station.

27. The method of claim 20, wherein the first station is a user equipment (UE) and the second station is a relay station.

28. An apparatus for wireless communication, comprising:

means for determining a subframe to send data from a first station to a second station;

means for determining a part of the subframe used by the second station to transmit control information; and

means for transmitting data from the first station to the second station in remaining part of the subframe.

29. The apparatus of claim 28, further comprising:

means for selecting a modulation and coding scheme (MCS) based on transmission of the data in only the remaining part of the subframe instead of an entire subframe; and

means for processing the data in accordance with the selected MCS.

30. The apparatus of claim 28, wherein the subframe comprises a control portion and a data portion, wherein the data is transmitted in the entire data portion if the second station is not transmitting control information in the subframe and is transmitted in only part of the data portion if the second station is transmitting control information in the subframe.

31. The apparatus of claim 28, wherein timing of the first station is offset by N symbol periods relative to timing of the second station, where N is one or greater, and wherein the offset of N symbol periods is selected to avoid overlapping of control information and reference signal sent by the first station with control information and reference signal sent by the second station.

32. A method for wireless communication, comprising:

determining a first partition of downlink resources into backhaul downlink resources available for a base station to transmit to a relay station and access downlink resources available for the relay station to transmit to user equipments (UEs);

determining a second partition of uplink resources into backhaul uplink resources available for the relay station to transmit to the base station and access uplink resources available for the UEs to transmit to the relay station; and

communicating on the downlink and uplink resources in accordance with the first and second partitions.

33. The method of claim 32, wherein the first partition is based on a first ratio between the backhaul downlink resources and the access downlink resources, and wherein the second partition is based on a second ratio between the backhaul uplink resources and the access uplink resources, the second ratio being different from the first ratio.

34. The method of claim 32, wherein the communicating on the downlink and uplink resources comprises

receiving first data on the backhaul downlink resources from the base station, and

sending acknowledgement (ACK) information for the first data on the backhaul uplink resources to the base station.

35. The method of claim 34, wherein the communicating on the downlink and uplink resources further comprises

sending second data on the access downlink resources to a UE, and

receiving ACK information for the second data on the access uplink resources from the UE.

36. The method of claim 32, wherein the communicating on the downlink and uplink resources comprises

sending data on the backhaul downlink resources to the relay station, and

receiving acknowledgement (ACK) information for the data on the backhaul uplink resources from the relay station.

37. The method of claim 32, wherein resources comprise subframes, wherein the first partition comprises backhaul downlink subframes and access downlink subframes, and wherein the second partition comprises backhaul uplink subframes and access uplink subframes.

38. The method of claim 37, wherein the access downlink subframes comprise subframes 0 and 5 of each radio frame comprising subframes 0 through 9.

39. The method of claim 37, wherein in each radio frame comprising subframes 0 through 9, the backhaul downlink subframes comprise subframes 4 and 9, the backhaul uplink subframes comprise subframes 3 and 8, the access downlink subframes comprise subframes 0, 1, 5 and 6, and the access uplink subframes comprise subframes 2 and 7.

40. The method of claim 37, wherein in each radio frame comprising subframes 0 through 9, the backhaul downlink subframes comprise subframes 3 and 9, the backhaul uplink subframes comprise subframe 7, the access downlink subframes comprise subframes 0, 1, 4, 5, 6 and 8, and the access uplink subframes comprise subframe 2.

41. The method of claim 37, wherein in each radio frame comprising subframes 0 through 9, the backhaul downlink subframes comprise subframes 7 and 9, the backhaul uplink subframes comprise subframe 2, the access downlink subframes comprise subframes 0, 1, 5, 6 and 8, and the access uplink subframes comprise subframes 3 and 4.

42. The method of claim 37, wherein in each radio frame comprising subframes 0 through 9, the backhaul downlink subframes comprise subframes 6, 7 and 9, the backhaul uplink subframes comprise subframe 2, the access downlink subframes comprise subframes 0, 1, 4, 5 and 8, and the access uplink subframes comprise subframe 3.

43. An apparatus for wireless communication, comprising:

means for determining a first partition of downlink resources into backhaul downlink resources available for a base station to transmit to a relay station and access downlink resources available for the relay station to transmit to user equipments (UEs);

means for determining a second partition of uplink resources into backhaul uplink resources available for the relay station to transmit to the base station and access uplink resources available for the UEs to transmit to the relay station; and

means for communicating on the downlink and uplink resources in accordance with the first and second partitions.

44. The apparatus of claim 43, wherein the first partition is based on a first ratio between the backhaul downlink resources and the access downlink resources, and wherein the second partition is based on a second ratio between the backhaul uplink resources and the access uplink resources, the second ratio being different from the first ratio.

45. The apparatus of claim 43, wherein the means for communicating on the downlink and uplink resources comprises

means for receiving first data on the backhaul downlink resources from the base station, and

means for sending acknowledgement (ACK) information for the first data on the backhaul uplink resources to the base station.

46. The apparatus of claim 45, wherein the means for communicating on the downlink and uplink resources further comprises

means for sending second data on the access downlink resources to a UE, and

means for receiving ACK information for the second data on the access uplink resources from the UE.

47. The apparatus of claim 43, wherein the means for communicating on the downlink and uplink resources comprises

means for sending data on the backhaul downlink resources to the relay station, and

means for receiving acknowledgement (ACK) information for the data on the backhaul uplink resources from the relay station.