TECHNIQUES FOR SUPPORTING RELAY OPERATION IN WIRELESS COMMUNICATION SYSTEMS

• US 20100080139A1
• 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 8,971,241 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• 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 bitmap may be sent by a base station and/or a relay station to identify subframes of at least two types in multiple radio frames. For example, the bitmap may indicate whether each subframe covered by the bitmap is of a first type or a second type. UEs may use the bitmap to control their operation. For example, a UE may perform channel estimation or measurement for the subframes of the first type and may skip channel estimation and measurement for the subframes of the second type. In another aspect, a base station may transmit data and/or control information on resources not used by a relay station to transmit a reference signal. This may avoid interference to the reference signal from the relay station, which may improve performance for UEs communicating with the relay station.

Claims

1. A method for wireless communication, comprising:

generating a bitmap covering a plurality of radio frames, each radio frame comprising a plurality of subframes, the bitmap identifying subframes of at least two types in the plurality of radio frames; and

transmitting the bitmap to user equipments (UEs).

2. The method of claim 1, wherein the subframes of at least two types comprise multicast/broadcast single frequency network (MBSFN) subframes and regular subframes.

3. The method of claim 1, wherein the subframes of at least two types comprise blank subframes and regular subframes.

4. The method of claim 1, wherein the bitmap covers four radio frames.

5. The method of claim 1, wherein the bitmap is generated by a relay station and transmitted to the UEs.

6. The method of claim 1, wherein the bitmap is generated by a base station and transmitted to the UEs.

7. An apparatus for wireless communication, comprising:

means for generating a bitmap covering a plurality of radio frames, each radio frame comprising a plurality of subframes, the bitmap identifying subframes of at least two types in the plurality of radio frames; and

means for transmitting the bitmap to user equipments (UEs).

8. The apparatus of claim 7, wherein the subframes of at least two types comprise multicast/broadcast single frequency network (MBSFN) subframes and regular subframes.

9. The apparatus of claim 7, wherein the subframes of at least two types comprise blank subframes and regular subframes.

10. The apparatus of claim 7, wherein the bitmap covers four radio frames.

11. An apparatus for wireless communication, comprising:

at least one processor configured to generate a bitmap covering a plurality of radio frames, each radio frame comprising a plurality of subframes, the bitmap identifying subframes of at least two types in the plurality of radio frames, and to send the bitmap to user equipments (UEs).

12. The apparatus of claim 11, wherein the subframes of at least two types comprise multicast/broadcast single frequency network (MBSFN) subframes and regular subframes.

13. The apparatus of claim 11, wherein the subframes of at least two types comprise blank subframes and regular subframes.

14. The apparatus of claim 11, wherein the bitmap covers four radio frames.

15. A computer program product, comprising:

a computer-readable medium comprising;

code for causing at least one computer to generate a bitmap covering a plurality of radio frames, each radio frame comprising a plurality of subframes, the bitmap identifying subframes of at least two types in the plurality of radio frames, and

code for causing the at least one computer to send the bitmap to user equipments (UEs).

16. A method for wireless communication, comprising:

performing channel estimation or measurement for subframes of a first type; and

skipping channel estimation and measurement for subframes of a second type different from the first type.

17. The method of claim 16, further comprising:

receiving a bitmap identifying the subframes of the first type and the subframes of the second type.

18. The method of claim 16, further comprising:

receiving the subframes of the first type time division multiplexed with the subframes of the second type.

19. The method of claim 16, wherein the subframes of the first type include a reference signal, and wherein the channel estimation or measurement is performed based on the reference signal.

20. The method of claim 16, wherein the subframes of the first type and the subframes of the second type are designated by a base station.

21. The method of claim 16, wherein the subframes of the first type comprise regular subframes and the subframes of the second type comprise multicast/broadcast single frequency network (MBSFN) subframes.

22. An apparatus for wireless communication, comprising:

means for performing channel estimation or measurement for subframes of a first type; and

means for skipping channel estimation and measurement for subframes of a second type different from the first type.

23. The apparatus of claim 22, further comprising:

means for receiving a bitmap identifying the subframes of the first type and the subframes of the second type.

24. The apparatus of claim 22, wherein the subframes of the first type include a reference signal, and wherein the channel estimation or measurement is performed based on the reference signal.

25. A method for wireless communication, comprising:

identifying resources not used by a relay station to transmit a reference signal;

sending control information, or data, or both by a base station on the identified resources.

26. The method of claim 25, wherein the identified resources comprise at least one orthogonal frequency division multiplexing (OFDM) symbol in a data portion of a multicast/broadcast single frequency network (MBSFN) subframe.

27. The method of claim 25, wherein the identified resources comprise at least one resource block in a data portion of a multicast/broadcast single frequency network (MBSFN) subframe.

28. An apparatus for wireless communication, comprising:

means for identifying resources not used by a relay station to transmit a reference signal; and

means for sending control information, or data, or both by a base station on the identified resources.

29. The apparatus of claim 28, wherein the identified resources comprise at least one orthogonal frequency division multiplexing (OFDM) symbol in a data portion of a multicast/broadcast single frequency network (MBSFN) subframe.

30. The apparatus of claim 28, wherein the identified resources comprise at least one resource block in a data portion of a multicast/broadcast single frequency network (MBSFN) subframe.

31. A method for wireless communication, comprising:

determining a subframe reserved for a first station; and

sending no transmissions in the reserved subframe by a second station to allow the first station to communicate with one or more other stations in the reserved subframe.

32. The method of claim 31, wherein the first station is a relay station, the second station is a base station, and the one or more other stations are one or more user equipments (UEs).

33. The method of claim 31, wherein the first station is a base station, the second station is a relay station, and the one or more other stations are one or more user equipments (UEs).

34. An apparatus for wireless communication, comprising:

means for determining a subframe reserved for a first station; and

means for sending no transmissions in the reserved subframe by a second station to allow the first station to communicate with one or more other stations in the reserved subframe.

35. The apparatus of claim 34, wherein the first station is a relay station, the second station is a base station, and the one or more other stations are one or more user equipments (UEs).

36. The apparatus of claim 34, wherein the first station is a base station, the second station is a relay station, and the one or more other stations are one or more user equipments (UEs).