Repetition techniques for autonomous uplink transmissions
Methods, systems, and devices for wireless communications are described that provide improved repetition techniques for autonomous uplink transmissions. Configuration information may be provided from a base station to a user equipment (UE) for autonomous uplink transmissions, that may indicate initial resources for an initial uplink transmission slot and retransmission resources for a number of retransmissions. Time resources within the retransmission resources may be configured to provide enhanced reliability, such as by being configured in non-contiguous slots to avoid one or more other transmission channels. Time resources within slots may also be configured to prevent persistent collisions with autonomous uplink transmissions or retransmissions of two or more different UEs.
1. An apparatus for wireless communications at a user equipment (UE), comprising: a processor, memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to:
receive configuration information for uplink communications, the configuration information indicating uplink resources for two or more repetitions of an uplink transmission in a set of transmission slots, wherein time resources within different slots of the set of transmission slots comprise different sets of time symbols within respective slots for at least one of the two or more repetitions of the uplink transmission;
transmit a first repetition of the uplink transmission via first uplink resources in a first slot of the set of transmission slots; and
transmit a second repetition of the uplink transmission via at least second uplink resources in a second slot of the set of transmission slots.
2. The apparatus method of claim 1 , wherein the uplink resources of the first slot and the second slot have a non-uniform pattern.
3. The apparatus of claim 1 , wherein the different sets of time symbols within respective slots are non-overlapping with one or more configured downlink resources.
4. The apparatus of claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to: transmit a third repetition of the uplink transmission via third uplink resources in the second slot of the set of transmission slots, wherein the second uplink resources and the third uplink resources occupy different time resources within the second slot.
5. The apparatus of claim 1 , wherein the uplink resources comprise a plurality of sets of time symbols within each slot of the set of transmission slots, and wherein retransmissions in different slots of the set of transmission slots use different sets of time symbols from the plurality of sets of time symbols.
6. The apparatus method of claim 1 , wherein the configuration information indicates:
a preconfigured pattern that is to be used by the UE for one or more transmission slots of the set of transmission slots.
7. The apparatus method of claim 1 , wherein:
the second slot of the set of transmission slots is included in a first subset of slots that is non-contiguous with the first slot.
8. The apparatus of claim 7 , wherein the first subset of slots are configured in every Mth slot within the set of transmission slots, and wherein a value of M is provided in the configuration information.
9. The apparatus of claim 1 , wherein the uplink resources span a plurality of slots of the set of transmission slots, and wherein the first slot has a first set of frequency resources and a subsequent slot of the set of transmission slots has a second set of frequency resources that spans a different number of frequency resources than the first set of frequency resources.
10. The apparatus method of claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to:
receive an early termination indication associated with the uplink transmission; and
discontinue transmissions of at least one of the two or more repetitions of the uplink transmission, based at least in part on the early termination indication.
11. The apparatus of claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to:
receive a time hopping offset that is used to repeatedly shift forward a starting symbol of time resources indicated by a start and length indicator value (SLIV) for each repetition of the uplink transmission; or
receive a sequence of different time offsets that indicate a starting time resource for each repetition of the uplink transmission.
12. The apparatus of claim 1 , wherein the configuration information is received via radio resource control (RRC) signaling, downlink control information (DCI) through a physical downlink control channel, a group common PDCCH transmission, or any combinations thereof.
13. An apparatus for wireless communications at an access network entity, comprising: a processor, memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to:
transmit configuration information to at least a first user equipment (UE) to configure the first UE for uplink transmissions, the configuration information indicating uplink resources for two or more repetitions of an uplink transmission in a set of transmission slots, wherein time resources within different slots of the set of transmission slots comprise different sets of time symbols within respective slots for at least one of the two or more repetitions of the uplink transmission;
receive a first repetition of the uplink transmission from the first UE via first uplink resources in a first slot of the set of transmission slots; and
receive a second repetition of the uplink transmission from the first UE via at least second uplink resources in a second slot of the set of transmission slots.
14. The apparatus method of claim 13 , wherein:
the different sets of time symbols within respective slots are non-overlapping with one or more configured downlink resources.
15. The apparatus method of claim 13 , wherein the instructions are further executable by the processor to cause the apparatus to:
receive a third repetition of the uplink transmission from the first UE via third uplink resources in the second slot of the set of transmission slots, wherein the second uplink resources and the third uplink resources occupy different time resources within the second slot.
16. The apparatus of claim 13 , wherein the instructions are further executable by the processor to cause the apparatus to: receive a third repetition of the uplink transmission from the first UE via third uplink resources in the second slot of the set of transmission slots that is non-contiguous with the first slot.
17. The apparatus of claim 16 , wherein every Mth slot within the set of transmission slots is configured for repetitions of the uplink transmission, and wherein a value of M is provided in the configuration information.
18. The apparatus of claim 13 , wherein the uplink resources of the first slot and the second slot have a non-uniform pattern.
19. The apparatus of claim 18 , wherein the different sets of time symbols within respective slots are non-overlapping with one or more configured downlink resources.
20. The apparatus of claim 13 , wherein the uplink resources comprise a plurality of sets of time symbols within each slot of the set of transmission slots, and wherein retransmissions in different slots of the set of transmission slots use different sets of time symbols from the plurality of sets of time symbols.
21. The apparatus of claim 20 , wherein the configuration information indicates a preconfigured pattern for the first UE for one or more transmission slots of the set of transmission slots.
22. The apparatus of claim 13 , wherein the uplink resources span a plurality of slots of the set of transmission slots, and wherein the first slot has a first set of frequency resources and a subsequent slot of the set of transmission slots has a second set of frequency resources that spans more frequency resources than the first set of frequency resources.
23. The apparatus method of claim 13 , wherein the instructions are further executable by the processor to cause the apparatus to:
determine that the uplink transmission is successfully received at the access network entity;
transmit an early termination indication associated with the uplink transmission to the first UE; and
discontinue attempts to receive the uplink transmission, based at least in part on the early termination indication.
24. The apparatus of claim 13 , wherein the configuration information comprises one or more of:
a time hopping offset that is used to repeatedly shift forward a starting symbol of time resources indicated by a start and length indicator value (SLIV) for each repetition of the uplink transmission; or
a sequence of different time offsets that indicate a starting time resource for each repetition of the uplink transmission.
25. A method for wireless communications at a user equipment (UE), comprising:
receiving configuration information for uplink communications, the configuration information indicating uplink resources for two or more repetitions of an uplink transmission in a set of transmission slots, wherein time resources within different slots of the set of transmission slots comprise different sets of time symbols within respective slots for at least one of the two or more repetitions of the uplink transmission;
transmitting a first repetition of the uplink transmission via first uplink resources in a first slot of the set of transmission slots; and
transmitting a second repetition of the uplink transmission via at least second uplink resources in a second slot of the set of transmission slots.
26. The method of claim 25 , further comprising:
transmitting a third repetition of the uplink transmission via third uplink resources in the second slot of the set of transmission slots, wherein the second uplink resources and the third uplink resources occupy different time resources within the second slot.
27. The method of claim 25 , wherein the uplink resources of the first slot and the second slot have a uniform or a non-uniform pattern.
28. A method for wireless communications at a base station, comprising: transmitting configuration information to at least a first user equipment (UE) to configure the first UE for uplink transmissions, the configuration information indicating uplink resources for two or more repetitions of an uplink transmission in a set of transmission slots, wherein time resources within different slots of the set of transmission slots comprise different sets of time symbols within respective slots for at least one of the two or more repetitions of the uplink transmission;
receiving a first repetition of the uplink transmission from the first UE via first uplink resources in a first slot of the set of transmission slots; and
receiving a second repetition of the uplink transmission from the first UE via at least second uplink resources in a second slot of the set of transmission slots.
29. The method of claim 28 , further comprising:
receiving a third repetition of the uplink transmission from the first UE via third uplink resources in the second slot of the set of transmission slots, wherein the second uplink resources and the third uplink resources occupy different time resources within the second slot.
30. The method of claim 28 , wherein the uplink resources of the first slot and the second slot have a uniform or a non-uniform pattern.