Bundling and hybrid automatic repeat request operation for enhanced machine-type communication
Methods, systems, and devices for wireless communication are described. A user equipment (UE), which may be a machine-type communication device and may have a half-duplex capability, may receive grants for uplink resources and downlink resources that overlap in time. The UE may prioritize the grants and either drop the low priority grant or may monitor a non-overlapping portion of resources assigned by the lower priority grant, for example. The UE may determine an acknowledgement mode for the downlink transmission based on one or more grants or on an explicit indication from a base station in some examples. A control format indicator may be interpreted based on the grant or on the bundling size. In some cases, the UE may identify a retuning time (e.g., for switching between transmit and receive modes or for switching frequencies) and may determine uplink and downlink bundling sizes based on the retuning time.
1. A method of wireless communication, comprising:
communicating using a first set of bundled resources for an uplink data channel;
determining that a second set of bundled resources for a downlink control channel comprises an uplink grant with a same hybrid automatic repeat request (HARQ) process identifier as the uplink data channel, an uplink grant with a different hybrid automatic repeat HARQ process identifier than the uplink data channel, or a downlink grant;
identifying a time difference between the first set of bundled resources and the second set of bundled resources; and
communicating using the second set of bundled resources based at least in part on the determining and the identifying.
2. The method of claim 1 , wherein the first set of bundled resources comprises a first bundling size that is less than or equal to a first threshold and the second set of bundled resources comprises a second bundling size that is less than or equal to a second threshold, and wherein the first and second thresholds are known a priori to a user equipment or base station.
3. The method of claim 1 , wherein the determination of whether the second set of bundled resources comprises the uplink grant is based at least in part on a periodicity of the second set of bundled resources or a maximum bundle size of the first set of bundled resources.
4. The method of claim 1 , further comprising:
determining that a third set of bundled resources assigned by a grant in the second set of bundled resources overlaps in time with a fourth set of bundled resources for another downlink control channel, wherein communicating using the second set of bundled resources comprises dropping the grant in the second set of bundled resources.
5. The method of claim 1 , further comprising:
determining that the second set of bundled resources comprises the uplink grant with the same HARQ process identifier as the uplink data channel, wherein communicating using the second set of bundled resources comprises dropping the uplink grant based at least on identifying the time difference.
6. The method of claim 1 , further comprising:
determining the time difference between the first set of bundled resources and the second set of bundled resources, wherein communicating using the second set of bundled resources is based at least in part on the time difference.
7. The method of claim 6 , wherein communicating using the first set of bundled resources comprises using a subset of the first set of bundled resources.
8. A method of wireless communication, comprising:
receiving a first grant for a first set of resources;
receiving a second grant for a second set of resources;
determining that a portion of the first set of resources indicated by the received first grant overlaps with a portion of the second set of resources indicated by the received second grant; and
communicating using the first set of resources or the second set of resources according to a prioritization between the first grant and the second grant based at least in part on the determination.
9. The method of claim 8 , further comprising:
dropping the first grant or the second grant based at least in part on the prioritization.
10. The method of claim 8 , wherein communicating using the first set of resources or the second set of resources comprises:
communicating using the first set of resources and a non-overlapped portion of the second set of resources.
11. The method of claim 8 , wherein the first and second sets of resources each comprise bundled resources of an uplink channel or a downlink channel.
12. An apparatus for wireless communication, comprising:
means for communicating using a first set of bundled resources for an uplink data channel;
means for determining that a second set of bundled resources for a downlink control channel comprises an uplink grant with a same hybrid automatic repeat request (HARQ) process identifier as the uplink data channel, an uplink grant with a different HARQ process identifier than the uplink data channel, or a downlink grant;
means for identifying a time difference between the first set of bundled resources and the second set of bundled resources; and
means for communicating using the second set of bundled resources based at least in part on the determining and the identifying.
13. The apparatus of claim 12 , wherein the first set of bundled resources comprises a first bundling size that is less than or equal to a first threshold and the second set of bundled resources comprises a second bundling size that is less than or equal to a second threshold, and wherein the first and second thresholds are known a priori to a user equipment or base station.
14. The apparatus of claim 12 , wherein the determination of whether the second set of bundled resources comprises the uplink grant is based at least in part on a periodicity of the second set of bundled resources or a maximum bundle size of the first set of bundled resources.
15. The apparatus of claim 12 , further comprising:
means for determining that a third set of bundled resources assigned by a grant in the second set of bundled resources overlaps in time with a fourth set of bundled resources for another downlink control channel, wherein communicating using the second set of bundled resources comprises dropping the grant in the second set of bundled resources.
16. The apparatus of claim 12 , further comprising:
means for determining that the second set of bundled resources comprises the uplink grant with the same HARQ process identifier as the uplink data channel, wherein communicating using the second set of bundled resources comprises dropping the uplink grant based at least on identifying the time difference.
17. The apparatus of claim 12 , further comprising:
means for determining the time difference between the first set of bundled resources and the second set of bundled resources, wherein communicating using the second set of bundled resources is based at least in part on the time difference.
18. The apparatus of claim 17 , wherein the means for communicating using the first set of bundled resources comprises using a subset of the first set of bundled resources.
19. An apparatus for wireless communication, comprising:
means for receiving a first grant for a first set of resources;
means for receiving a second grant for a second set of resources;
means for determining that a portion of the first set of resources indicated by the received first grant overlaps with a portion of the second set of resources indicated by the received second grant; and
means for communicating using the first set of resources or the second set of resources according to a prioritization between the first grant and the second grant based at least in part on the determination.
20. The apparatus of claim 19 , further comprising:
means for dropping the first grant or the second grant based at least in part on the prioritization.
21. The apparatus of claim 19 , wherein the means for communicating using the first set of resources or the second set of resources comprises:
means for communicating using the first set of resources and a non-overlapped portion of the second set of resources.
22. The apparatus of claim 19 , wherein the first and second sets of resources each comprise bundled resources of an uplink channel or a downlink channel.
23. An apparatus for wireless communication, comprising:
a processor;
memory in electronic communication with the processor; and
instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to:
communicate using a first set of bundled resources for an uplink data channel;
determine that a second set of bundled resources for a downlink control channel comprises an uplink grant with a same hybrid automatic repeat request (HARQ) process identifier as the uplink data channel, an uplink grant with a different hybrid automatic repeat request (HARQ) process identifier than the uplink data channel, or a downlink grant;
identify a time difference between the first set of bundled resources and the second set of bundled resources; and
communicate using the second set of bundled resources based at least in part on the determination and the identification.
24. The apparatus of claim 23 , wherein the first set of bundled resources comprises a first bundling size that is less than or equal to a first threshold and the second set of bundled resources comprises a second bundling size that is less than or equal to a second threshold, and wherein the first and second thresholds are known a priori to a user equipment or base station.
25. The apparatus of claim 23 , wherein the determination of whether the second set of bundled resources comprises the uplink grant is based at least in part on a periodicity of the second set of bundled resources or a maximum bundle size of the first set of bundled resources.
26. The apparatus of claim 23 , wherein the instructions are operable to cause the apparatus to:
determine that a third set of bundled resources assigned by a grant in the second set of bundled resources overlaps in time with a fourth set of bundled resources for another downlink control channel, wherein communicating using the second set of bundled resources comprises dropping the grant in the second set of bundled resources.
27. The apparatus of claim 23 , wherein the instructions are operable to cause the apparatus to:
determine that the second set of bundled resources comprises the uplink grant with the same HARQ process identifier as the uplink data channel, wherein communicating using the second set of bundled resources comprises dropping the uplink grant based at least on identifying the time difference.
28. The apparatus of claim 23 , wherein the instructions are operable to cause the apparatus to:
determine the time difference between the first set of bundled resources and the second set of bundled resources, wherein communicating using the second set of bundled resources is based at least in part on the time difference.
29. The apparatus of claim 28 , wherein communicating using the first set of bundled resources comprises using a subset of the first set of bundled resources.
30. An apparatus for wireless communication, comprising:
a processor;
memory in electronic communication with the processor; and
instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to:
receive a first grant for a first set of resources;
receive a second grant for a second set of resources;
determine that a portion of the first set of resources indicated by the received first grant overlaps with a portion of the second set of resources indicated by the received second grant; and
communicate using the first set of resources or the second set of resources according to a prioritization between the first grant and the second grant based at least in part on the determination.
31. The apparatus of claim 30 , wherein the instructions are operable to cause the apparatus to:
drop the first grant or the second grant based at least in part on the prioritization.
32. The apparatus of claim 30 , wherein the instructions are operable to cause the apparatus to:
communicate using the first set of resources and a non-overlapped portion of the second set of resources.
33. The apparatus of claim 30 , wherein the first and second sets of resources each comprise bundled resources of an uplink channel or a downlink channel.
34. A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable to:
communicate using a first set of bundled resources for an uplink data channel;
determine that a second set of bundled resources for a downlink control channel comprises an uplink grant with a same hybrid automatic repeat request (HARQ) process identifier as the uplink data channel, an uplink grant with a different hybrid automatic repeat request (HARQ) process identifier than the uplink data channel, or a downlink grant;
identify a time difference between the first set of bundled resources and the second set of bundled resources; and
communicate using the second set of bundled resources based at least in part on the determination and the identification.
35. A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable to:
receive a first grant for a first set of resources;
receive a second grant for a second set of resources;
determine that a portion of the first set of resources indicated by the received first grant overlaps with a portion of the second set of resources indicated by the received second grant; and
communicate using the first set of resources or the second set of resources according to a prioritization between the first grant and the second grant based at least in part on the determination.