BUNDLING OF ACK INFORMATION IN A WIRELESS COMMUNICATION SYSTEM

• US 20090279460A1
• Filed: 05/05/2009
• Published: 11/12/2009
• Est. Priority Date: 05/07/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Sarkar, Sandip
• Granted Patent: US 8,634,333 B2
• Time in Patent Office: Days
• US Class Current: 370/280
• CPC Class Codes: H04L 1/16 in which the return channel carries supervisory signals, e.g. repetition request signals
• CPC Class Codes: H04L 1/1621 Group acknowledgement, i.e. the acknowledgement message defining a range of identifiers, e.g. of sequence numbers
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems

Abstract

Techniques for bundling acknowledgement (ACK) information in a wireless communication system are described. In one design, a user equipment (UE) may receive multiple codewords in at least one downlink subframe. The UE may decode the multiple codewords and determine an ACK or a negative acknowledgement (NACK) for each codeword based on decoding result. The UE may bundle the ACKs and NACKs for the multiple codewords to obtain bundled ACK information. In one design, the UE may generate (i) a bundled ACK if ACKs are obtained for all codewords or (ii) a bundled NACK if a NACK is obtained for any codeword. The UE may send the bundled ACK information as feedback for the multiple codewords. The UE may receive retransmissions of the multiple codewords if a bundled NACK is sent and may receive new codewords if a bundled ACK is sent.

Claims

1. A method of receiving data in a wireless communication system, comprising:

receiving multiple codewords in at least one subframe;

decoding the multiple codewords;

determining an acknowledgement (ACK) or a negative acknowledgement (NACK) for each codeword based on decoding result for the codeword;

bundling ACKs and NACKs for the multiple codewords to obtain bundled ACK information; and

sending the bundled ACK information as feedback for the multiple codewords.

2. The method of claim 1, wherein the multiple codewords are received in at least one downlink subframe and the bundled ACK information is sent in an uplink subframe in a time division duplexed (TDD) system with an asymmetric downlink-uplink configuration having more downlink subframes than uplink subframes.

3. The method of claim 1, wherein the multiple codewords are received in multiple subframes, one codeword in each subframe.

4. The method of claim 1, wherein the multiple codewords are received via a multiple-input multiple-output (MIMO) transmission in one subframe.

5. The method of claim 1, wherein the bundling ACKs and NACKs for the multiple codewords comprises

generating a bundled ACK if ACKs are obtained for all of the multiple codewords, and

generating a bundled NACK if a NACK is obtained for any one of the multiple codewords.

6. The method of claim 1, wherein the bundled ACK information comprises a bundled ACK or a bundled NACK for the multiple codewords, the method further comprising:

receiving retransmissions of the multiple codewords if a bundled NACK is sent for the multiple codewords; and

receiving new codewords if a bundled ACK is sent for the multiple codewords.

7. The method of claim 1, wherein the bundling ACKs and NACKs for the multiple codewords comprises

obtaining ACK, NACK, or discontinuous transmission (DTX) for each of the multiple codewords, and

mapping ACKs, NACKs and DTXs for the multiple codewords to multiple bits of the bundled ACK information based on a predetermined mapping.

8. The method of claim 1, wherein the bundled ACK information comprises multiple bundled ACKs/NACKs for multiple sets of codewords formed with the multiple codewords, each bundled ACK/NACK comprising a bundled ACK or a bundled NACK for one set of codewords.

9. The method of claim 8, wherein the bundling the ACKs and NACKs for the multiple codewords comprises determining the bundled ACK/NACK for each set of codewords based on ACKs and NACKs for the codewords in the set of codewords.

10. The method of claim 8, further comprising:

receiving retransmission of each set of codewords for which a bundled NACK is sent; and

receiving a new set of codewords for each set of codewords for which a bundled ACK is sent.

11. The method of claim 8, wherein each set of codewords is received in one subframe.

12. The method of claim 8, wherein each set of codewords comprises codewords sent in one layer of multiple-input multiple-output (MIMO) transmissions received in multiple subframes.

13. An apparatus for wireless communication, comprising:

at least one processor configured to receive multiple codewords in at least one subframe, to decode the multiple codewords, to determine an acknowledgement (ACK) or a negative acknowledgement (NACK) for each codeword based on decoding result for the codeword, to bundle ACKs and NACKs for the multiple codewords to obtain bundled ACK information, and to send the bundled ACK information as feedback for the multiple codewords.

14. The apparatus of claim 13, wherein the at least one processor is configured to generate a bundled ACK if ACKs are obtained for all of the multiple codewords, and to generate a bundled NACK if a NACK is obtained for any one of the multiple codewords.

15. The apparatus of claim 13, wherein the at least one processor is configured to receive retransmissions of the multiple codewords if a bundled NACK is sent for the multiple codewords, and to receive new codewords if a bundled ACK is sent for the multiple codewords.

16. The apparatus of claim 13, wherein the at least one processor is configured to obtain ACK, NACK, or discontinuous transmission (DTX) for each of the multiple codewords, and to map ACKs, NACKs and DTXs for the multiple codewords to multiple bits of the bundled ACK information based on a predetermined mapping.

17. The apparatus of claim 13, wherein the bundled ACK information comprises multiple bundled ACKs/NACKs for multiple sets of codewords formed with the multiple codewords, each bundled ACK/NACK comprising a bundled ACK or a bundled NACK for one set of codewords, and wherein the at least one processor is configured to determine the bundled ACK/NACK for each set of codewords based on ACKs and NACKs for the codewords in the set of codewords.

18. The apparatus of claim 17, wherein the at least one processor is configured to receive retransmission of each set of codewords for which a bundled NACK is sent, and to receive a new set of codewords for each set of codewords for which a bundled ACK is sent.

19. An apparatus for wireless communication, comprising:

means for receiving multiple codewords in at least one subframe;

means for decoding the multiple codewords;

means for determining an acknowledgement (ACK) or a negative acknowledgement (NACK) for each codeword based on decoding result for the codeword;

means for bundling ACKs and NACKs for the multiple codewords to obtain bundled ACK information; and

means for sending the bundled ACK information as feedback for the multiple codewords.

20. The apparatus of claim 19, wherein the means for bundling ACKs and NACKs for the multiple codewords comprises

means for generating a bundled ACK if ACKs are obtained for all of the multiple codewords, and

means for generating a bundled NACK if a NACK is obtained for any one of the multiple codewords.

21. The apparatus of claim 19, wherein the bundled ACK information comprises a bundled ACK or a bundled NACK for the multiple codewords, the apparatus further comprising:

means for receiving retransmissions of the multiple codewords if a bundled NACK is sent for the multiple codewords; and

means for receiving new codewords if a bundled ACK is sent for the multiple codewords.

22. The apparatus of claim 19, wherein the means for bundling ACKs and NACKs for the multiple codewords comprises

means for obtaining ACK, NACK, or discontinuous transmission (DTX) for each of the multiple codewords, and

means for mapping ACKs, NACKs and DTXs for the multiple codewords to multiple bits of the bundled ACK information based on a predetermined mapping.

23. The apparatus of claim 19, wherein the bundled ACK information comprises multiple bundled ACKs/NACKs for multiple sets of codewords formed with the multiple codewords, each bundled ACK/NACK comprising a bundled ACK or a bundled NACK for one set of codewords, and wherein the means for bundling the ACKs and NACKs for the multiple codewords comprises

means for determining the bundled ACK/NACK for each set of codewords based on ACKs and NACKs for the codewords in the set of codewords.

24. The apparatus of claim 23, further comprising:

means for receiving retransmission of each set of codewords for which a bundled NACK is sent; and

means for receiving a new set of codewords for each set of codewords for which a bundled ACK is sent.

25. A computer program product, comprising:

a computer-readable medium comprising;

code for causing at least one computer to receive multiple codewords in at least one subframe,

code for causing the at least one computer to decode the multiple codewords,

code for causing the at least one computer to determine an acknowledgement (ACK) or a negative acknowledgement (NACK) for each codeword based on decoding result for the codeword,

code for causing the at least one computer to bundle ACKs and NACKs for the multiple codewords to obtain bundled ACK information, and

code for causing the at least one computer to send the bundled ACK information as feedback for the multiple codewords.

26. A method of sending data in a wireless communication system, comprising:

sending multiple codewords in at least one subframe to a receiver;

receiving bundled acknowledgement (ACK) information generated by the receiver based on ACKs and negative acknowledgements (NACKs) for the multiple codewords; and

determining whether to resend the multiple codewords or to send new codewords based on the bundled ACK information.

27. The method of claim 26, wherein the multiple codewords are sent in at least one downlink subframe and the bundled ACK information is received in an uplink subframe in a time division duplexed (TDD) system with an asymmetric downlink-uplink configuration having more downlink subframes than uplink subframes.

28. The method of claim 26, wherein the multiple codewords are sent in multiple subframes, one codeword in each subframe.

29. The method of claim 26, wherein the multiple codewords are sent via a multiple-input multiple-output (MIMO) transmission in one subframe.

30. The method of claim 26, wherein the bundled ACK information comprises a bundled ACK if ACKs are obtained by the receiver for all of the multiple codewords or a bundled NACK if a NACK is obtained by the receiver for any one of the multiple codewords.

31. The method of claim 26, further comprising:

resending the multiple codewords if a bundled NACK is received for the multiple codewords; and

sending new codewords if a bundled ACK is received for the multiple codewords.

32. The method of claim 31, wherein the resending the multiple codewords comprises

sending a retransmission of each codeword comprising systematic bits and parity bits for the codeword.

33. The method of claim 26, wherein the bundled ACK information comprises multiple bundled ACKs/NACKs for multiple sets of codewords formed with the multiple codewords, each bundled ACK/NACK comprising a bundled ACK or a bundled NACK for one set of codewords.

34. The method of claim 33, further comprising:

resending each set of codewords for which a bundled NACK is received; and

sending a new set of codewords for each set of codewords for which a bundled ACK is received.

35. An apparatus for wireless communication, comprising:

at least one processor configured to send multiple codewords in at least one subframe to a receiver, to receive bundled acknowledgement (ACK) information generated by the receiver based on ACKs and negative acknowledgements (NACKs) for the multiple codewords, and to determine whether to resend the multiple codewords or to send new codewords based on the bundled ACK information.

36. The apparatus of claim 35, wherein the bundled ACK information comprises a bundled ACK or a bundled NACK for the multiple codewords, and wherein the at least one processor is configured to resend the multiple codewords if a bundled NACK is received, and to send new codewords if a bundled ACK is received.

37. The apparatus of claim 35, wherein the bundled ACK information comprises multiple bundled ACKs/NACKs for multiple sets of codewords formed with the multiple codewords, each bundled ACK/NACK comprising a bundled ACK or a bundled NACK for one set of codewords, and wherein the at least one processor is configured to resend each set of codewords for which a bundled NACK is received, and to send a new set of codewords for each set of codewords for which a bundled ACK is received.