Techniques for communicating on an uplink in a shared radio frequency spectrum band

1. A method for wireless communication at a user equipment (UE), comprising:

receiving a first uplink grant for a reference scheduled transmission burst including a plurality of contiguous transmission time intervals (TTIs) transmitted over a shared radio frequency spectrum band, wherein the first uplink grant includes: a first indication that the first uplink grant is associated with a first scheduled TTI of the reference scheduled transmission burst, a second indication of a position of the first scheduled TTI within the reference scheduled transmission burst, or a combination thereof;

transmitting during at least one TTI of the reference scheduled transmission burst, in accordance with the first uplink grant, the transmitting beginning during a first transmission TTI;

receiving an indication of a reference TTI, the reference TTI being used for transmission by the UE during the reference scheduled transmission burst; and

determining a contention window size usable by the UE to contend for access to the shared radio frequency spectrum band, the determining based at least in part on a relationship between the first scheduled TTI, the reference TTI, and the first transmission TTI.

2. The method of claim 1 , wherein the first uplink grant for the reference scheduled transmission burst comprises the second indication of the position of the first scheduled TTI within the reference scheduled transmission burst.

3. The method of claim 1 , wherein the indication of the reference TTI is relative to the first scheduled TTI.

4. The method of claim 1 , wherein the relationship includes the first transmission TTI being earlier than the reference TTI, the first transmission TTI being later than the reference TTI, or the first transmission TTI being the same as the reference TTI.

5. An apparatus for wireless communication 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 a first uplink grant for a reference scheduled transmission burst including a plurality of contiguous transmission time intervals (TTIs) transmitted over a shared radio frequency spectrum band, wherein the first uplink grant includes: a first indication that the first uplink grant is associated with a first scheduled TTI of the reference scheduled transmission burst, a second indication of a position of the first scheduled TTI within the reference scheduled transmission burst, or a combination thereof;

transmit during at least one TTI of the reference scheduled transmission burst, in accordance with the first uplink grant, the transmitting beginning during a first transmission TTI;

receive an indication of a reference TTI, the reference TTI being used for transmission by the UE during the reference scheduled transmission burst; and

determine a contention window size usable by the UE to contend for access to the shared radio frequency spectrum band, the determining based at least in part on a relationship between the first scheduled TTI, the reference TTI, and the first transmission TTI.

6. The apparatus of claim 5 , wherein the first uplink grant for the reference scheduled transmission burst comprises the second indication of the position of the first scheduled TTI within the reference scheduled transmission burst.

7. The apparatus of claim 5 , wherein the indication of the reference TTI is relative to the first scheduled TTI.

8. The apparatus of claim 5 , wherein the relationship includes the first transmission TTI being earlier than the reference TTI, the first transmission TTI being later than the reference TTI, or the first transmission TTI being the same as the reference TTI.

9. An apparatus for wireless communication at a user equipment (UE), comprising:

means for receiving a first uplink grant for a reference scheduled transmission burst including a plurality of contiguous transmission time intervals (TTIs) transmitted over a shared radio frequency spectrum band, wherein the first uplink grant includes: a first indication that the first uplink grant is associated with a first scheduled TTI of the reference scheduled transmission burst, a second indication of a position of the first scheduled TTI within the reference scheduled transmission burst, or a combination thereof;

means for transmitting during at least one TTI of the reference scheduled transmission burst, in accordance with the first uplink grant, the transmitting beginning during a first transmission TTI;

means for receiving an indication of a reference TTI, the reference TTI being used for transmission by the UE during the reference scheduled transmission burst; and

means for determining a contention window size usable by the UE to contend for access to the shared radio frequency spectrum band, the determining based at least in part on a relationship between the first scheduled TTI, the reference TTI, and the first transmission TTI.

10. The apparatus of claim 9 , wherein the first uplink grant for the reference scheduled transmission burst comprises the second indication of the position of the first scheduled TTI within the reference scheduled transmission burst.

11. The apparatus of claim 9 , wherein the indication of the reference TTI is relative to the first scheduled TTI.

12. The apparatus of claim 9 , wherein the relationship includes the first transmission TTI being earlier than the reference TTI, the first transmission TTI being later than the reference TTI, or the first transmission TTI being the same as the reference TTI.

13. A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE), the code comprising instructions executable by a processor to:

receive a first uplink grant for a reference scheduled transmission burst including a plurality of contiguous transmission time intervals (TTIs) transmitted over a shared radio frequency spectrum band, wherein the first uplink grant includes: a first indication that the first uplink grant is associated with a first scheduled TTI of the reference scheduled transmission burst, a second indication of a position of the first scheduled TTI within the reference scheduled transmission burst, or a combination thereof;

transmit during at least one TTI of the reference scheduled transmission burst, in accordance with the first uplink grant, the transmitting beginning during a first transmission TTI;

receive an indication of a reference TTI, the reference TTI being used for transmission by the UE during the reference scheduled transmission burst; and

determine a contention window size usable by the UE to contend for access to the shared radio frequency spectrum band, the determining based at least in part on a relationship between the first scheduled TTI, the reference TTI, and the first transmission TTI.

14. The non-transitory computer-readable medium of claim 13 , wherein the first uplink grant for the reference scheduled transmission burst comprises the second indication of the position of the first scheduled TTI within the reference scheduled transmission burst.

15. The non-transitory computer-readable medium of claim 13 , wherein the indication of the reference TTI is relative to the first scheduled TTI.

16. The non-transitory computer-readable medium of claim 13 , wherein the relationship includes the first transmission TTI being earlier than the reference TTI, the first transmission TTI being later than the reference TTI, or the first transmission TTI being the same as the reference TTI.