HARQ ACK/NACK transmission for multi-carrier operation
View Patent ↗Techniques for sending ACK/NACK information in a multi-carrier wireless communication network are disclosed. In one aspect, a plurality of ACK/NACK transmission techniques are selectively employed by a multi-carrier user equipment (UE) to reduce the number of bits of ACK/NACK information to send and/or increase the number of payload bits available for sending the ACK/NACK information. The ACK/NACK transmission techniques may include an orthogonal sequence reduction technique, a channel selection technique, a spatial bundling technique, a carrier bundling technique, and/or a subframe bundling technique. The ACK/NACK transmission techniques may be prioritized based on the number of carriers on which data transmissions are received, a payload size available for carrying ACK/NACK information, and/or other factors. The multi-carrier UE can utilize different ACK/NACK transmission techniques in connection with different subsets of its configured carriers.
1. A method for wireless communication, comprising:
receiving data transmissions on a plurality of carriers configured for use by a user equipment (UE);
determining acknowledgement/negative acknowledgement (ACK/NACK) bits for the data transmissions at the UE;
determining a plurality of ACK/NACK transmission techniques comprising at least a cross-carrier bundling technique in which ACK/NACK bits corresponding to data transmissions on a subset of two or more carriers in the plurality of carriers are bundled and a bundling technique that is not associated with the cross-carrier bundling technique;
determining, based at least in part on a total number of the ACK/NACK bits for the data transmissions received on the plurality of carriers, to use the cross-carrier bundling technique for sending the ACK/NACK bits for the data transmissions, wherein the bundling technique that is not associated with the cross-carrier bundling technique is prioritized over the cross-carrier bundling technique when the total number of the ACK/NACK bits is less than a threshold;
determining a subset of at least two carriers of the plurality of carriers for which to bundle the ACK/NACK bits using the cross-carrier bundling technique;
bundling ACK/NACK bits corresponding to the data transmissions on the at least two carriers of the subset with the cross-carrier bundling technique;
bundling ACK/NACK bits corresponding to the data transmissions with the bundling technique that is not associated with the cross-carrier bundling technique; and
sending, by the UE, ACK/NACK information comprising ACK/NACK bits bundled according to the bundling techniques.
2. The method of claim 1 , wherein the determining the subset of at least two carriers for which to bundle ACK/NACK bits comprises selecting the at least two carriers from a same frequency band.
3. The method of claim 1 , wherein determining the subset of the at least two carriers for which to bundle ACK/NACK bits is further based on a number of carriers on which the data transmissions are received.
4. The method of claim 1 , wherein the determining the subset of at least two carriers for which to bundle ACK/NACK bits is further based on a number of payload bits available to send the ACK/NACK information.
5. The method of claim 1 , wherein the determining the subset of at least two carriers for which to bundle ACK/NACK bits comprises selecting the at least two carriers based on a data transmission mode for each of the plurality of carriers.
6. The method of claim 1 , wherein determining the subset of the at least two carriers for which to bundle ACK/NACK bits comprises:
receiving a configuration message indicating a group of carriers for which to bundle ACK/NACK bits across carriers; and
determining the at least two carriers in accordance with the group of carriers.
7. The method of claim 1 , wherein the determining the subset of at least two carriers for which to bundle ACK/NACK bits comprises:
selecting the at least two carriers based on a target termination for each of the plurality of carriers.
8. The method of claim 1 , wherein the determining the subset of at least two carriers for which to bundle ACK/NACK bits comprises:
determining interference characteristics associated with each carrier in the plurality of carriers, and
selecting the at least two carriers based on a similarity of interference characteristics.
9. The method of claim 1 , wherein the ACK/NACK information further comprises at least one ACK/NACK bit for at least one data transmission on at least one remaining carrier in the plurality of carriers, with no bundling of the at least one ACK/NACK bit across carriers.
10. The method of claim 1 , wherein the sending ACK/NACK information comprises sending the ACK/NACK information on a single uplink carrier associated with the plurality of carriers.
11. The method of claim 1 , wherein the bundling ACK/NACK bits corresponding to the data transmissions with the bundling technique that is not associated with the cross-carrier bundling technique comprises:
performing spatial bundling of ACK/NACK bits for data transmissions on at least one carrier in the plurality of carriers.
12. The method of claim 1 , wherein the bundling ACK/NACK bits corresponding to the data transmissions with the bundling technique that is not associated with the cross-carrier bundling technique comprises:
performing subframe bundling of ACK/NACK bits for data transmissions on at least one carrier in a plurality of subframes, the at least one carrier being among the plurality of carriers.
13. An apparatus for wireless communication, comprising:
means for receiving data transmissions on a plurality of carriers configured for use by a user equipment (UE);
means for determining acknowledgement/negative acknowledgement (ACK/NACK) bits for the data transmissions on the plurality of carriers at the UE;
means for determining a plurality of ACK/NACK transmission techniques comprising at least a cross-carrier bundling technique in which ACK/NACK bits corresponding to data transmissions on a subset of two or more carriers in the plurality of carriers are bundled and a bundling technique that is not associated with the cross-carrier bundling technique;
means for determining, based at least in part on a total number of the ACK/NACK bits for the data transmissions received on the plurality of carriers, to use the cross-carrier bundling technique for sending the ACK/NACK bits for the data transmissions, wherein the bundling technique that is not associated with the cross-carrier bundling technique is prioritized over the cross-carrier bundling technique when the total number of the ACK/NACK bits is less than a threshold;
means for determining a subset of at least two carriers of the plurality of carriers for which to bundle the ACK/NACK bits using the cross-carrier bundling technique;
means for bundling ACK/NACK bits corresponding to the data transmissions on the at least two carriers of the subset with the cross-carrier bundling technique;
means for bundling ACK/NACK bits corresponding to the data transmissions with the bundling technique that is not associated with the cross-carrier bundling technique; and
means for sending ACK/NACK information comprising ACK/NACK bits bundled according to the bundling techniques.
14. The apparatus of claim 13 , wherein the means for determining the subset of at least two carriers for which to bundle ACK/NACK bits is further based on a number of carriers on which data transmissions are received, a number of payload bits available to send the ACK/NACK information, a frequency band of each of the plurality of carriers, a data transmission mode for each of the plurality of carriers, a target termination for each of the plurality of carriers, interference characteristics associated with each of the plurality of carriers, a configuration message for the UE, or any combination thereof.
15. The apparatus of claim 13 , wherein the ACK/NACK information further comprises at least one ACK/NACK bit for at least one data transmission on at least one remaining carrier in the plurality of carriers, with no bundling of the at least one ACK/NACK bit across carriers.
16. An apparatus for wireless communication, comprising:
at least one processor configured to:
receive data transmissions on a plurality of carriers configured for use by a user equipment (UE),
determine acknowledgement/negative acknowledgement (ACK/NACK) bits for the data transmissions on the plurality of carriers at the UE,
determine a plurality of ACK/NACK transmission techniques comprising at least a cross-carrier bundling technique in which ACK/NACK bits corresponding to data transmissions on a subset of two or more carriers in the plurality of carriers are bundled and a bundling technique that is not associated with the cross-carrier bundling technique;
determine, based at least in part on a total number of the ACK/NACK bits for the data transmissions received on the plurality of carriers, to use the cross-carrier bundling technique for sending the ACK/NACK bits for the data transmissions, wherein the bundling technique that is not associated with the cross-carrier bundling technique is prioritized over the cross-carrier bundling technique when the total number of the ACK/NACK bits is less than a threshold;
determine a subset at least two carriers of the plurality of carriers for which to bundle the ACK/NACK bits using the cross-carrier bundling technique,
bundle ACK/NACK bits corresponding to the data transmissions on the at least two carrier of the subset with the cross-carrier bundling technique,
bundle ACK/NACK bits corresponding to the data transmissions with the bundling technique that is not associated with the cross-carrier bundling technique, and
send ACK/NACK information comprising ACK/NACK bits bundled according to the bundling techniques; and
a memory coupled to the at least one processor.
17. The apparatus of claim 16 , wherein the determining the subset of at least two carriers for which to bundle ACK/NACK bits is further based on a number of carriers on which data transmissions are received, a number of payload bits available to send the ACK/NACK information, a frequency band of each of the plurality of carriers, a data transmission mode for each of the plurality of carriers, a target termination for each of the plurality of carriers, interference characteristics associated with each of the plurality of carriers, a configuration message for the UE, or any combination thereof.
18. The apparatus of claim 16 , wherein the ACK/NACK information further comprises at least one ACK/NACK bit for at least one data transmission on at least one remaining carrier in the plurality of carriers, with no bundling of the at least one ACK/NACK bit across carriers.
19. A non-transitory computer-readable medium storing computer executable code, comprising code for:
receiving data transmissions on a plurality of carriers configured for use by a user equipment (UE),
determining acknowledgement/negative acknowledgement (ACK/NACK) bits for the data transmissions on the plurality of carriers at the UE,
determining a plurality of ACK/NACK transmission techniques in which ACK/NACK bits corresponding to data transmissions on a subset of two or more carriers in the plurality of carriers are bundled and a bundling technique that is not associated with the cross-carrier bundling technique,
determining, based at least in part on a total number of the ACK/NACK bits for the data transmissions received on the plurality of carriers, to use the carrier-carrier bundling technique for sending the ACK/NACK bits for the data transmissions, wherein the bundling technique that is not associated with the cross-carrier bundling technique is prioritized over the cross-carrier bundling technique when the total number of the ACK/NACK bits is less than a threshold;
determining a subset of at least two carriers of the plurality of carriers for which to bundle the ACK/NACK bits using the cross-carrier bundling technique,
bundling the ACK/NACK bits corresponding to the data transmissions on the at least two carriers of the subset with the cross-carrier bundling technique, and
sending ACK/NACK information comprising ACK/NACK bits bundled according to the bundling techniques.
20. A method for wireless communication, comprising:
sending data transmissions to a user equipment (UE) on a plurality of carriers configured for use by the UE;
receiving from the UE acknowledgement/negative acknowledgement (ACK/NACK) information comprising at least one bundled ACK/NACK bit relating to data transmissions on at least two carriers of the plurality of carriers, the at least two carriers selected based on a total number of ACK/NACK bits for the data transmissions on the plurality of carriers;
determining a plurality of ACK/NACK transmission techniques comprising at least a cross-carrier bundling technique in which ACK/NACK bits corresponding to data transmissions on a subset of two or more carriers in the plurality of carriers are bundled and a bundling technique that is not associated with the cross-carrier bundling technique; and
obtaining ACK/NACK bits for the data transmissions on the at least two carriers based on the at least one bundled ACK/NACK bit.
21. The method of claim 20 , further comprising:
determining whether to terminate or continue each of the data transmissions on the at least two carriers based on the ACK/NACK bits.
22. An apparatus for wireless communication, comprising:
means for sending data transmissions to a user equipment (UE) on a plurality of carriers configured for use by the UE;
means for receiving from the UE acknowledgement/negative acknowledgement (ACK/NACK) information comprising at least two bundled ACK/NACK bits relating to data transmissions on at least two carriers of the plurality of carriers, the at least two carriers selected based on a total number of the ACK/NACK bits for the data transmissions on the plurality of carriers;
means for determining a plurality of ACK/NACK transmission techniques comprising at least a cross-carrier bundling technique in which ACK/NACK bits corresponding to data transmissions on a subset of two or more carriers in the plurality of carriers are bundled and a bundling technique that is not associated with the cross-carrier bundling technique; and
means for obtaining ACK/NACK bits for the data transmissions on the at least two carriers based on the at least two bundled ACK/NACK bits, wherein at least one bit of the bundled ACK/NACK bits is bundled according to the cross-carrier bundling technique and at least one other bit of the bundled ACK/NACK bits is bundled according to the bundling technique that is not associated with the cross-carrier bundling technique.
23. The apparatus of claim 22 , further comprising:
means for determining whether to terminate or continue each of the data transmissions on the at least two carriers based on the ACK/NACK bits.
24. A method for wireless communication, comprising:
receiving data transmissions on a plurality of carriers configured for use by a user equipment (UE);
determining, at the UE, acknowledgement/negative acknowledgement (ACK/NACK) bits for the data transmissions on the plurality of carriers;
determining a plurality of ACK/NACK transmission techniques available to the UE in a multi-carrier operation, the plurality of ACK/NACK transmission techniques comprising at least a cross-carrier bundling technique in which ACK/NACK bits corresponding to data transmissions on a subset of two or more carriers in the plurality of carriers are bundled and
a technique that is not associated with the cross-carrier bundling technique, wherein the technique that is not associated with the cross-carrier bundling technique is selected based on a total number of the ACK/NACK bits for the data transmissions on the plurality of carriers or a number of carriers on which data transmissions are received;
bundling ACK/NACK bits corresponding to the data transmissions on the at least two carriers of the subset with the cross-carrier bundling technique;
bundling ACK/NACK bits corresponding to the data transmissions on another subset of carriers with the bundling technique that is not associated with the cross-carrier bundling technique; and
sending the bundled ACK/NACK bits for the data transmissions.
25. The method of claim 24 , wherein the determining the plurality of ACK/NACK transmission techniques available to the UE in a multi-carrier operation comprises:
selecting an orthogonal sequence reduction technique when a total number of ACK/NACK bits for the data transmissions on the plurality of carriers is greater than a predetermined value or when the number of carriers on which data transmissions are received is greater than a predetermined threshold.
26. The method of claim 24 , wherein the determining the plurality of ACK/NACK transmission techniques available to the UE in a multi-carrier operation comprises:
selecting a spatial bundling technique when a total number of ACK/NACK bits for the data transmissions on the plurality of carriers is greater than a predetermined value or when the number of carriers on which data transmissions are received is greater than a predetermined threshold.
27. The method of claim 24 , wherein the determining the plurality of ACK/NACK transmission techniques available to the UE in a multi-carrier operation comprises:
selecting a channel selection technique when a total number of ACK/NACK bits for the data transmissions on the plurality of carriers is greater than a predetermined value of when the number of carriers on which data transmissions are received is greater than a predetermined threshold.
28. The method of claim 24 , wherein the bundled ACK/NACK bits are bundled based on an order of prioritization of the plurality of ACK/NACK transmission techniques.
29. The method of claim 24 , wherein the plurality of ACK/NACK transmission techniques includes an orthogonal sequence reduction technique for sending ACK/NACK bits using an orthogonal sequence of a shorter length than a nominal length.
30. The method of claim 24 , wherein the plurality of ACK/NACK transmission techniques includes a spatial bundling technique for bundling ACK/NACK bits for multiple data transmissions sent concurrently on a carrier with spatial multiplexing.
31. The method of claim 24 , wherein the plurality of ACK/NACK transmission techniques includes a channel selection technique for sending ACK/NACK information using one of multiple resources.
32. The method of claim 24 , wherein the plurality of ACK/NACK transmission techniques includes a carrier bundling technique for bundling ACK/NACK bits for multiple packets sent on multiple carriers in a subframe.
33. The method of claim 24 , wherein the plurality of ACK/NACK transmission techniques includes a subframe bundling technique for bundling ACK/NACK bits for multiple packets sent on a carrier in multiple subframes.
34. An apparatus for wireless communication, comprising:
means for receiving data transmissions on a plurality of carriers configured for use by a user equipment (UE);
means for determining, at the UE, acknowledgement/negative acknowledgement (ACK/NACK) bits for the data transmissions on the plurality of carriers;
means for determining a plurality of ACK/NACK transmission techniques available to the UE in a multi-carrier operation, the plurality of ACK/NACK transmission techniques comprising at least a cross-carrier bundling technique in which ACK/NACK bits corresponding to data transmissions on a subset of two or more carriers in the plurality of carriers are bundled and
at least one ACK/NACK transmission technique that is not associated with the cross-carrier bundling technique, wherein the at least one ACK/NACK transmission technique that is not associated with the cross-carrier bundling technique is selected based on a total number of the ACK/NACK bits for the data transmissions on the plurality of carriers or a number of carriers on which data transmissions are received;
means for bundling ACK/NACK bits corresponding to the data transmissions on the at least two carriers of the subset with the cross-carrier bundling technique;
means for bundling ACK/NACK bits corresponding to the data transmissions on another subset of carriers with the bundling technique that is not associated with the cross-carrier bundling technique; and
means for sending the ACK/NACK bits for the data transmissions on the plurality of carriers based on the at least one ACK/NACK transmission technique.
35. The apparatus of claim 34 , wherein the at least one ACK/NACK transmission technique is selected further based on an order or prioritization of the plurality of ACK/NACK transmission techniques.
36. The apparatus of claim 34 , wherein the at least one ACK/NACK transmission technique further includes a subframe bundling technique, or a combination of the subframe bundling technique, an orthogonal sequence reduction technique, a spatial bundling technique, a channel selection technique, or the cross-carrier bundling technique.
37. An apparatus for wireless communication, comprising:
at least one processor configured to:
receive data transmissions on a plurality of carriers configured for use by a user equipment (UE),
determine acknowledgement/negative acknowledgement (ACK/NACK) bits for the data transmissions on the plurality of carriers,
determine a plurality of ACK/NACK transmission techniques available to the UE in a multi-carrier operation, the plurality of ACK/NACK transmission techniques comprising at least a cross-carrier bundling technique in which ACK/NACK bits corresponding to data transmissions on a subset of two or more carriers in the plurality of carriers are bundled and
at least one ACK/NACK transmission technique that is not associated with the cross-carrier bundling technique, wherein the at least one ACK/NACK transmission technique that is not associated with the cross-carrier bundling technique is selected based on a total number of the ACK/NACK bits for the data transmissions on the plurality of carriers or a number of carriers on which data transmissions are received,
bundle ACK/NACK bits corresponding to the data transmissions on the at least two carriers of the subset with the cross-carrier bundling technique,
bundle ACK/NACK bits corresponding to the data transmissions on another subset of carriers with the bundling technique that is not associated with the cross-carrier bundling technique, and
send the bundled ACK/NACK bits for the data transmissions on the plurality of carriers; and
a memory coupled to the at least one processor.
38. The apparatus of claim 37 , wherein the at least one ACK/NACK transmission technique is selected further based on an order of prioritization of the plurality of ACK/NACK transmission techniques.
39. The apparatus of claim 37 , wherein the at least one ACK/NACK transmission technique includes an orthogonal sequence reduction technique, a spatial bundling technique, a channel selection technique, a carrier bundling technique, a subframe bundling technique, or a combination thereof.
40. A non-transitory computer-readable medium storing computer executable code, comprising code for:
receiving data transmissions on a plurality of carriers configured for use by a user equipment (UE),
determining acknowledgement/negative acknowledgement (ACK/NACK) bits for the data transmissions on the plurality of carriers,
determining a plurality of ACK/NACK transmission techniques available to the UE in a multi-carrier operation, the plurality of ACK/NACK transmission techniques comprising at least a cross-carrier bundling technique in which ACK/NACK bits corresponding to data transmissions on a subset of two or more carriers in the plurality of carriers are bundled and
a technique that is not associated with the cross-carrier bundling technique, wherein the technique that is not associated with the cross-carrier bundling technique is selected based on a total number of the ACK/NACK bits for the data transmissions on the plurality of carriers or a number of carriers on which data transmissions are received,
bundling ACK/NACK bits corresponding to the data transmissions on the at least two carriers of the subset with the cross-carrier bundling technique,
bundling ACK/NACK bits corresponding to the data transmissions on another subset of carriers with the bundling technique that is not associated with the cross-carrier bundling technique, and
sending the bundled ACK/NACK bits for the data transmissions on the plurality of carriers.
41. A method for wireless communication, comprising:
sending data transmissions to a user equipment (UE) on a plurality of carriers configured for use by the UE;
receiving, from the UE, ACK/NACK information corresponding to the data transmissions on the plurality of carriers;
determining a plurality of ACK/NACK transmission techniques available to the UE in a multi-carrier operation, the plurality of ACK/NACK transmission techniques comprising at least a cross-carrier bundling technique in which ACK/NACK bits corresponding to data transmissions on a subset of two or more carriers in the plurality of carriers are bundled and
a technique that is not associated with the cross-carrier bundling technique, wherein the technique that is not associated with the cross-carrier bundling technique is selected based on a total number of the ACK/NACK bits for the data transmissions on the plurality of carriers or a number of carriers on which data transmissions are received; and
recovering ACK/NACK bits for the data transmissions on the plurality of carriers based on the ACK/NACK information, wherein the ACK/NACK bits corresponding to the data transmissions on the subset of the two or more carriers were bundled based on the cross-carrier bundling technique and the ACK/NACK bits corresponding to the data transmission on another subset of carriers were bundled based on the bundling technique that is not associated with the cross-carrier bundling technique.
42. The method of claim 41 , further comprising:
determining whether to terminate or continue each of the data transmissions on the plurality of carriers based on the ACK/NACK bits.
43. An apparatus for wireless communication, comprising:
means for sending data transmissions to a user equipment (UE) on a plurality of carriers configured for use by the UE;
means for receiving, from the UE, ACK/NACK information corresponding to the data transmissions on the plurality of carriers;
means for determining a plurality of ACK/NACK transmission techniques available to the UE in a multi-carrier operation, the plurality of ACK/NACK transmission techniques comprising at least a cross-carrier bundling technique in which ACK/NACK bits corresponding to data transmissions on a subset of two or more carriers in the plurality of carriers are bundled and
a technique that is not associated with the cross-carrier bundling technique, wherein the technique that is not associated with the cross-carrier bundling technique is selected based on a total number of the ACK/NACK bits for the data transmissions on the plurality of carriers or a number of carriers on which data transmissions are received; and
means for recovering ACK/NACK bits for the data transmissions on the plurality of carriers based on the ACK/NACK information, wherein the ACK/NACK bits corresponding to the data transmissions on the subset of the two or more carriers were bundled based on the cross-carrier bundling technique and the ACK/NACK bits corresponding to the data transmission on another subset of carriers were bundled based on the bundling technique that is not associated with the cross-carrier bundling technique.
44. The apparatus of claim 43 , further comprising:
means for determining whether to terminate or continue each of the data transmissions on the plurality of carriers based on the ACK/NACK bits.