Techniques for communicating on an uplink in a shared radio frequency spectrum band
Techniques are described for wireless communication. One method includes detecting a first reference signal received from a user equipment (UE) in a reference scheduled transmission burst including a plurality of contiguous transmission time intervals (TTIs) received over a shared radio frequency spectrum band; identifying a reference TTI in which the first reference signal is received; determining a contention window size usable by the UE to contend for access to the shared radio frequency spectrum band; and transmitting an indication of the determined contention window size to the UE.
1. A method for wireless communication at a user equipment (UE), comprising:
receiving, in a first downlink transmission time interval (TTI) of a scheduled transmission burst, over a shared radio frequency spectrum band, an indication of a downlink-uplink TTI configuration for the scheduled transmission burst, wherein the downlink-uplink TTI configuration indicates a first number of upcoming downlink TTIs to follow the first downlink TTI before a first downlink-uplink transition, the first number being relative to the first downlink TTI in which the UE receives the indication, and a second number of uplink TTIs to follow the first downlink-uplink transition in the scheduled transmission burst before a second downlink-uplink transition of the scheduled transmission burst; and
determining, based at least in part on the second downlink-uplink transition indicated by the downlink-uplink TTI configuration, a timing of a next downlink TTI in the scheduled transmission burst relative to the first downlink TTI in which the UE receives the indication.
2. The method of claim 1 , further comprising:
receiving, in each of at least one additional downlink TTI of the scheduled transmission burst, an additional indication of an additional downlink-uplink TTI configuration for a portion of the scheduled transmission burst following the additional downlink TTI.
3. The method of claim 1 , further comprising:
receiving, in the first downlink TTI, at least one of: a second indication of a downlink TTI duration, a third indication of an uplink TTI duration, or a combination thereof.
4. The method of claim 1 , wherein the first downlink TTI comprises a downlink subframe and the downlink-uplink TTI configuration comprises a downlink-uplink subframe configuration.
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, in a first downlink transmission time interval (TTI) of a scheduled transmission burst, over a shared radio frequency spectrum band, an indication of a downlink-uplink TTI configuration for the scheduled transmission burst, wherein the downlink-uplink TTI configuration indicates a first number of upcoming downlink TTIs to follow the first downlink TTI before a first downlink-uplink transition, the first number being relative to the first downlink TTI in which the UE receives the indication, and a second number of uplink TTIs to follow the first downlink-uplink transition in the scheduled transmission burst before a second downlink-uplink transition of the scheduled transmission burst; and
determine, based at least in part on the second downlink-uplink transition indicated by the downlink-uplink TTI configuration, a timing of a next downlink TTI in the scheduled transmission burst relative to the first downlink TTI in which the UE receives the indication.
6. The apparatus of claim 5 , wherein the instructions are further executable by the processor to cause the apparatus to:
receive, in each of at least one additional downlink TTI of the scheduled transmission burst, an additional indication of an additional downlink-uplink TTI configuration for a portion of the scheduled transmission burst following the additional downlink TTI.
7. The apparatus of claim 5 , wherein the instructions are further executable by the processor to cause the apparatus to:
receive, in the first downlink TTI, at least one of: a second indication of a downlink TTI duration, a third indication of an uplink TTI duration, or a combination thereof.
8. The apparatus of claim 5 , wherein the first downlink TTI comprises a downlink subframe and the downlink-uplink TTI configuration comprises a downlink-uplink subframe configuration.
9. An apparatus for wireless communication at a user equipment (UE), comprising:
means for receiving, in a first downlink transmission time interval (TTI) of a scheduled transmission burst, over a shared radio frequency spectrum band, an indication of a downlink-uplink TTI configuration for the scheduled transmission burst, wherein the downlink-uplink TTI configuration indicates a first number of upcoming downlink TTIs to follow the first downlink TTI before a first downlink-uplink transition, the first number being relative to the first downlink TTI in which the UE receives the indication, and a second number of uplink TTIs to follow the first downlink-uplink transition in the scheduled transmission burst before a second downlink-uplink transition of the scheduled transmission burst; and
means for determining, based at least in part on the second downlink-uplink transition indicated by the downlink-uplink TTI configuration, a timing of a next downlink TTI in the scheduled transmission burst relative to the first downlink TTI in which the UE receives the indication.
10. The apparatus of claim 9 , further comprising:
means for receiving, in each of at least one additional downlink TTI of the scheduled transmission burst, an additional indication of an additional downlink-uplink TTI configuration for a portion of the scheduled transmission burst following the additional downlink TTI.
11. The apparatus of claim 9 , further comprising:
means for receiving, in the first downlink TTI, at least one of: a second indication of a downlink TTI duration, a third indication of an uplink TTI duration, or a combination thereof.
12. The apparatus of claim 9 , wherein the first downlink TTI comprises a downlink subframe and the downlink-uplink TTI configuration comprises a downlink-uplink subframe configuration.
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, in a first downlink transmission time interval (TTI) of a scheduled transmission burst, over a shared radio frequency spectrum band, an indication of a downlink-uplink TTI configuration for the scheduled transmission burst, wherein the downlink-uplink TTI configuration indicates a first number of upcoming downlink TTIs to follow the first downlink TTI before a first downlink-uplink transition, the first number being relative to the first downlink TTI in which the UE receives the indication, and a second number of uplink TTIs to follow the first downlink-uplink transition in the scheduled transmission burst before a second downlink-uplink transition of the scheduled transmission burst; and
determine, based at least in part on the second downlink-uplink transition indicated by the downlink-uplink TTI configuration, a timing of a next downlink TTI in the scheduled transmission burst relative to the first downlink TTI in which the UE receives the indication.
14. The non-transitory computer-readable medium of claim 13 , wherein the instructions are further executable to:
receive, in each of at least one additional downlink TTI of the scheduled transmission burst, an additional indication of an additional downlink-uplink TTI configuration for a portion of the scheduled transmission burst following the additional downlink TTI.
15. The non-transitory computer-readable medium of claim 13 , wherein the instructions are further executable to:
receive, in the first downlink TTI, at least one of: a second indication of a downlink TTI duration, a third indication of an uplink TTI duration, or a combination thereof.
16. The non-transitory computer-readable medium of claim 13 , wherein the first downlink TTI comprises a downlink subframe and the downlink-uplink TTI configuration comprises a downlink-uplink subframe configuration.