Autonomous uplink transmission techniques using shared radio frequency spectrum
Techniques for autonomous uplink (AUL) transmissions are provided that allow for efficient use of shared radio frequency spectrum band resources. A user equipment (UE) may determine a duration of an AUL transmission and modify an uplink waveform or provide an indication to a base station of one or more channel resources that may be available for base station transmissions, in order to more fully utilize shared radio frequency spectrum band resources within a maximum channel occupancy time (MCOT). A base station may activate or deactivate AUL transmissions through downlink control information (DCI) transmitted to the UE. A UE and base station may exchange various other control information to provide relatively efficient autonomous uplink transmissions and use of the shared radio frequency spectrum band resources.
1. A method for wireless communication, comprising:
receiving, from a base station, radio resource control (RRC) signaling including an autonomous uplink configuration for unscheduled autonomous uplink transmissions in a shared radio frequency spectrum band with the base station;
receiving downlink control information (DCI) for activating autonomous uplink transmissions;
activating the autonomous uplink transmissions based at least in part on receiving the DCI;
sensing, during a configured time duration, for activity on a channel of the shared radio frequency spectrum band based at least in part on activating the autonomous uplink transmissions;
contending for access to the channel of the shared radio frequency spectrum band in accordance with the autonomous uplink configuration based at least in part on sensing for activity on the channel; and
transmitting, to the base station, one or more autonomous uplink transmissions over the channel of the shared radio frequency spectrum band in accordance with the autonomous uplink configuration.
2. The method of claim 1 , further comprising:
receiving subsequent DCI that deactivates the autonomous uplink transmissions; and
discontinuing contending for access to the channel of the shared radio frequency spectrum band responsive to receiving the subsequent DCI.
3. The method of claim 1 , wherein the DCI comprises a cyclic redundancy check (CRC) field scrambled with an identifier.
4. The method of claim 3 , wherein a value of the identifier indicates that the DCI is associated with the autonomous uplink transmissions.
5. The method of claim 1 , wherein the autonomous uplink configuration enables the autonomous uplink transmissions on one or more transmit antennas according to a multiple input multiple output (MIMO) configuration.
6. An apparatus for wireless communication, comprising:
a processor;
memory coupled with the processor; and
instructions stored in the memory and executable by the processor to cause the apparatus to:
receive, from a base station, radio resource control (RRC) signaling including an autonomous uplink configuration for unscheduled autonomous uplink transmissions in a shared radio frequency spectrum band with the base station;
receive downlink control information (DCI) for activating autonomous uplink transmissions;
activating the autonomous uplink transmissions based at least in part on receiving the DCI;
sense, during a configured time duration, for activity on a channel of the shared radio frequency spectrum band based at least in part on activating the autonomous uplink transmissions;
contend for access to the channel of the shared radio frequency spectrum band in accordance with the autonomous uplink configuration based at least in part on sensing for activity on the channel; and
transmit, to the base station, one or more autonomous uplink transmissions over the channel of the shared radio frequency spectrum band in accordance with the autonomous uplink configuration.
7. The apparatus of claim 6 , wherein the instructions are further executable by the processor to cause the apparatus to:
receive subsequent DCI that deactivates the autonomous uplink transmissions; and
discontinue contending for access to the channel of the shared radio frequency spectrum band responsive to receiving the subsequent DCI.
8. The apparatus of claim 6 , wherein the DCI comprises a cyclic redundancy check (CRC) field scrambled with an identifier.
9. The apparatus of claim 8 , wherein a value of the identifier indicates that the DCI is associated with the autonomous uplink transmissions.
10. The apparatus of claim 6 , wherein the autonomous uplink configuration enables the autonomous uplink transmissions on one or more transmit antennas according to a multiple input multiple output (MIMO) configuration.
11. An apparatus for wireless communication, comprising:
means for receiving, from a base station, radio resource control (RRC) signaling including an autonomous uplink configuration for unscheduled autonomous uplink transmissions in a shared radio frequency spectrum band with the base station;
means for receiving downlink control information (DCI) for activating autonomous uplink transmissions;
means for activating the autonomous uplink transmissions based at least in part on receiving the DCI;
means for sensing, during a configured time duration, for activity on a channel of the shared radio frequency spectrum band based at least in part on activating the autonomous uplink transmissions;
means for contending for access to the channel of the shared radio frequency spectrum band in accordance with the autonomous uplink configuration based at least in part on sensing for activity on the channel; and
means for transmitting, to the base station, one or more autonomous uplink transmissions over the channel of the shared radio frequency spectrum band in accordance with the autonomous uplink configuration.
12. The apparatus of claim 11 , further comprising:
means for receiving subsequent DCI that deactivates the autonomous uplink transmissions; and
means for discontinuing contending for access to the channel of the shared radio frequency spectrum band responsive to receiving the subsequent DCI.
13. The apparatus of claim 11 , wherein the DCI comprises a cyclic redundancy check (CRC) field scrambled with an identifier.
14. The apparatus of claim 13 , wherein a value of the identifier indicates that the DCI is associated with the autonomous uplink transmissions.
15. The apparatus of claim 11 , wherein the autonomous uplink configuration enables the autonomous uplink transmissions on one or more transmit antennas according to a multiple input multiple output (MIMO) configuration.