Beam management in a wireless network
A wireless transmit/receive unit (WTRU) may monitor control resource sets (CORESETs) to receive a physical downlink control channel (PDCCH) having downlink control information (DCI) that includes a scheduling offset and an indicated beam for a scheduled physical downlink shared channel (PDSCH) reception. When the scheduling offset of the scheduled PDSCH is less than a threshold, a default beam of a transmission configuration indication (TCI) state may be utilized to receive the scheduled PDSCH. When the scheduling offset of the scheduled PDSCH is more than a threshold, the indicated beam is utilized to receive the scheduled PDSCH on a condition that a measured quality is above a measurement threshold or the default beam may be utilized when the measured quality is below the measurement threshold.
1. A wireless transmit/receive unit (WTRU) comprising:
a processor configured to determine that a first beam is associated with a first control resource set (CORESET) and that a second beam is associated with a second CORESET; and
a transceiver configured to receive at least one physical downlink control channel (PDCCH) transmission in a slot via one of the CORESETS, the PDCCH transmission comprising downlink control information (DCI), the DCI comprising scheduling information for a data transmission received via a physical downlink shared channel (PDSCH) transmission, the DCI comprising an indication of a beam for receiving the data transmission via the PDSCH transmission;
wherein the processor is further configured to:
determine whether to receive the data transmission via the beam indicated via the indication comprised in the DCI or via a reference beam associated with a reference CORESET, wherein the WTRU is configured to receive the data transmission via the reference beam associated with the reference CORESET based on a scheduling offset associated with the data transmission received via the PDSCH transmission being less than a threshold, and the WTRU is configured to receive the data transmission via the beam indicated via the indication in the DCI based on the scheduling offset associated with the data transmission received via the PDSCH transmission being greater than or equal to the threshold;
on condition that the scheduling offset associated with the data transmission received via the PDSCH transmission is less than the threshold, determine whether the first CORESET or the second CORESET is the reference CORESET for the data transmission received via the PDSCH transmission, wherein the WTRU is configured to determine which CORESET is the reference CORESET based on the slot, wherein the first CORESET is determined to be the reference CORESET for the data transmission based on the slot; and
wherein the transceiver is further configured to:
receive the data transmission via the PDSCH transmission using the first beam associated with the first CORESET when the scheduling offset associated with the data transmission received via the PDSCH transmission is less than the threshold, or
receive the data transmission via the PDSCH transmission using the beam indicated via the indication comprised in the DCI when the scheduling offset associated with the data transmission received via the PDSCH transmission is greater than or equal to the threshold.
2. The WTRU of claim 1 , wherein the first beam of the reference CORESET is determined based on a CORESET time location with respect to the data transmission on the PDSCH, and
wherein the CORESET time location with respect to the data transmission on the PDSCH is a latest time location with the plurality of configured CORESETs.
3. The WTRU of claim 1 , wherein the second beam is used for reception of the DCI on the PDCCH and the first beam is used for the plurality of data transmissions on the plurality of PDSCHs, when a plurality of data transmissions is scheduled for transmission on a plurality of PDSCHs.
4. The WTRU of claim 3 , wherein beams used for reception of the plurality of data transmissions are different, when a plurality of data transmissions utilizing the plurality of PDSCHs is scheduled over a plurality of slots by the DCI.
5. The WTRU of claim 1 , wherein the first beam is determined based on a lowest CORESET identification (ID).
6. The WTRU of claim 1 , wherein the reference CORESET is determined based on a slot number.
7. The WTRU of claim 1 , wherein the reference CORESET is determined based on one or more configured CORESETs monitored in the slot.
8. The WTRU of claim 1 , wherein the indication comprised in the DCI is indicated via a transmission configuration indication (TCI) field comprised in the DCI.
9. The WTRU of claim 1 , wherein the scheduling offset corresponds to an amount of time between reception of the PDCCH transmission comprising the DCI and reception of the data transmission via the PDSCH transmission.
10. A method performed by a wireless transmit/receive unit (WTRU), the method comprising:
determining that a first beam is associated with a first control resource set (CORESET) and that a second beam is associated with a second CORESET;
receiving at least one physical downlink control channel (PDCCH) transmission in a slot via one of the CORESETS, the PDCCH transmission comprising downlink control information (DCI), the DCI comprising scheduling information for a data transmission received via a physical downlink shared channel (PDSCH) transmission, the DCI comprising an indication of a beam for receiving the data transmission via the PDSCH transmission;
determining whether to receive the data transmission via the beam indicated via the indication comprised in the DCI or via a reference beam associated with a reference CORESET, wherein the WTRU is configured to receive the data transmission via the reference beam associated with the reference CORESET based on a scheduling offset associated with the data transmission received via the PDSCH transmission being less than a threshold, and wherein the data transmission is received via the beam indicated via the indication in the DCI based on the scheduling offset associated with the data transmission received via the PDSCH transmission being greater than or equal to the threshold;
on condition that the scheduling offset associated with the data transmission received via the PDSCH transmission is less than the threshold, determining whether the first CORESET or the second CORESET is the reference CORESET for the data transmission received via the PDSCH transmission, wherein the WTRU is configured to determine which CORESET is the reference CORESET based on the slot, wherein the first CORESET is determined to be the reference CORESET for the data transmission based on the slot; and
receiving the data transmission via the PDSCH transmission using the first beam associated with the first CORESET when the scheduling offset associated with the data transmission received via the PDSCH transmission is less than the threshold, or
receiving the data transmission via the PDSCH transmission using the beam indicated via the indication comprised in the DCI when the scheduling offset associated with the data transmission received via the PDSCH transmission is greater than or equal to the threshold.
11. The method of claim 10 , wherein the CORESET time location with respect to the data transmission on the PDSCH is a latest time location with the plurality of configured CORESETs.
12. The method of claim 10 , wherein the second beam is used for reception of the DCI on the PDCCH and the first beam is used for the plurality of data transmissions on the plurality of PDSCHs, when a plurality of data transmissions is scheduled for transmission on a plurality of PDSCHs.
13. The method of claim 12 , wherein beams used for reception are different, when a plurality of data transmissions utilizing the plurality of PDSCHs is scheduled over a plurality of slots by the DCI.
14. The method of claim 10 , wherein the first beam is determined based on a lowest CORESET identification (ID).
15. The method of claim 10 , wherein the reference CORESET is determined based on one or more of the slot, a slot number, a configured CORESET monitored in the slot, and a CORESET time location with respect to the PDSCH.
16. The method of claim 10 , wherein the reference CORESET is determined based on a CORESET time location with respect to the data transmission on the PDSCH.
17. The method of claim 10 , wherein the reference CORESET is determined based on a slot number.
18. The method of claim 10 , wherein the reference CORESET is determined based on one or more configured CORESETs monitored in the slot.
19. The method of claim 10 , wherein the indication comprised in the DCI is indicated via a transmission configuration indication (TCI) field comprised in the DCI.
20. The method of claim 10 , wherein the scheduling offset corresponds to an amount of time between reception of the PDCCH transmission comprising the DCI and reception of the data transmission via the PDSCH transmission.