Transmitting a TB after successful LBT procedure
Apparatuses, methods, and systems are disclosed for transmitting data using unlicensed spectrum. One apparatus includes a memory comprising instructions executable by a processor to cause the apparatus to receive a single DCI comprising a grant for multiple transmission occasions and to perform a first LBT procedure for transmission of a first TB associated with a first transmission occasion of the grant, where the first LBT procedure results in LBT failure and where the first TB is associated with a first HARQ process. The instructions are further executable by the processor to cause the apparatus to transmit the first TB during a second transmission occasion of the grant associated with a second HARQ process in response to the first LBT procedure resulting in LBT failure.
1. A user equipment (“UE”) for wireless communication, comprising:
at least one memory; and
at least one processor coupled with the at least one memory and configured to cause the UE to:
receive a downlink control information (“DCI”) comprising a grant for multiple transmission occasions associated with different hybrid automatic repeat request (“HARQ”) processes, wherein the DCI identifies a first HARQ process associated with a first transmission occasion of the multiple transmission occasions;
generate a first transport block (“TB”) for the first HARQ process;
perform a first listen-before-talk (“LBT”) procedure for transmission of the first TB associated with the first transmission occasion, wherein the first LBT procedure results in LBT failure;
transmit the first TB during a second transmission occasion associated with a second HARQ process in response to the first LBT procedure resulting in LBT failure; and
map the first TB to the second HARQ process in response to the first LBT procedure resulting in LBT failure.
2. The UE of claim 1 , wherein the at least one processor is configured to cause the UE to:
perform a second LBT procedure for the second transmission occasion; and
transmit the first TB during the second transmission occasion based at least in part on the second LBT procedure resulting in LBT success.
3. The UE of claim 1 , wherein the first transmission occasion and the second transmission occasion have a same TB size, wherein a New Data Indicator is toggled for each of the first transmission occasion and the second transmission occasion, and wherein the first HARQ process is different than the second HARQ process.
4. The UE of claim 1 , wherein to transmit the first TB during the second transmission occasion, the at least one processor is configured to cause the UE to transmit in a first non-partial slot of the grant for multiple transmission occasions for which a respective LBT procedure is successful.
5. The UE of claim 1 , wherein the second transmission occasion is associated with a second TB, and wherein the at least one processor is configured to cause the UE to store the second TB in a transmission buffer of the first HARQ process in response to the transmission of the first TB using the second transmission occasion.
6. The UE of claim 5 , wherein the first TB comprises higher priority data than the second TB.
7. The UE of claim 1 , wherein the UE is configured with an autonomous UL (“AUL”) grant, wherein the first transmission occasion comprises a first AUL opportunity of the AUL grant and the second transmission occasion comprises a second AUL opportunity of the AUL grant.
8. The UE of claim 1 , wherein the DCI includes a one-bit flag indicating whether to modify Logical Channel Prioritization (“LCP”) rules for a predetermined number of transmission resources of the grant for multiple transmission occasions, wherein the instructions are executable by the at least one processor is configured to cause the UE to generate a second TB for a first of the predetermined number of transmission resources of the grant for multiple transmission occasions according to applicable LCP rules.
9. The UE of claim 8 , wherein to generate the second TB, the at least one processor is configured to cause the UE to allow only data from delay-tolerant logical channels in the predetermined number of transmission resources of the grant for multiple transmission occasions.
10. The UE of claim 8 , wherein the predetermined number of transmission resources are located at a beginning of the grant for multiple transmission occasions.
11. A method performed by a user equipment (“UE”), the method comprising:
receiving a downlink control information (“DCI”) comprising a grant for multiple transmission occasions associated with different hybrid automatic repeat request (“HARQ”) processes, wherein the DCI identifies a first HARQ process associated with a first transmission occasion of the multiple transmission occasions;
generating a first transport block (“TB”) for the first HARQ process;
performing a first listen-before-talk (“LBT”) procedure for transmission of the first TB associated with the first transmission occasion, wherein the first LBT procedure results in LBT failure;
transmitting the first TB during a second transmission occasion associated with a second HARQ process in response to the first LBT procedure resulting in LBT failure; and
mapping the first TB to the second HARQ process in response to the first LBT procedure resulting in LBT failure.
12. The method of claim 11 , further comprising performing a second LBT procedure for the second transmission occasion, wherein transmitting the first TB during the second transmission occasion is based at least in part on the second LBT procedure resulting in LBT success.
13. The method of claim 11 , wherein the first transmission occasion and the second transmission occasion have a same TB size, wherein a New Data Indicator is toggled for each of the first and second transmissions, and wherein the first HARQ process is different than the second HARQ process.
14. The method of claim 11 , wherein transmitting the first TB during the second transmission occasion comprises transmitting in a first non-partial slot of the grant for multiple transmission occasions for which a respective LBT procedure is successful.
15. The method of claim 11 , wherein the second transmission occasion is associated with a second TB, the method further comprising storing the second TB in a transmission buffer of the first HARQ process in response to transmitting the first TB using the second transmission occasion.
16. The method of claim 15 , wherein the first TB comprises higher priority data than the second TB.
17. The method of claim 11 , wherein the UE is configured with an autonomous UL (“AUL”) grant, wherein the first transmission occasion comprises a first AUL opportunity of the AUL grant and the second transmission comprises a second AUL opportunity of the AUL grant.
18. The method of claim 11 , wherein the DCI includes a one-bit flag indicating whether to modify Logical Channel Prioritization (“LCP”) rules for a predetermined number of transmission resources of the grant for multiple transmission occasions, the method further comprising generating a TB for a first of the predetermined number of transmission resources of the grant for multiple transmission occasions according to applicable LCP rules.
19. The method of claim 18 , wherein generating the TB comprises allowing only data from delay-tolerant logical channels in the predetermined number of resources of the grant for multiple transmission occasions.
20. The method of claim 18 , wherein the predetermined number of resources are located at a beginning of the grant for multiple transmission occasions.