Group-based beam management
A WTRU may include a memory and a processor. The processor may be configured to receive beam grouping information from a gNB or transmission and reception point (TRP). The beam grouping information may indicate a group of beams that the WTRU may report using group-based reporting. The group-based reporting may be a reduced level of reporting compared to a beam-based reporting. The group-based report may include measurement information for a representative beam. The representative beam may be one of the beams in the group or represents an average of the beams in the group. Alternatively, the representative beam may be a beam that has a maximum measurement value compared to other beams in the group. The group-based report may include a reference signal received power (RSRP) for the representative beam and a differential RSRP for each additional beam in the beam group.
1. A wireless transmit/receive unit (WTRU), comprising:
a processor and a transceiver which are configured to:
receive a first channel state information reference signal (CSI-RS) configuration message, wherein the CSI-RS configuration message includes information indicating a first group of beams associated with a first level of beam reporting that uses a first cycle,
receive a second CSI-RS configuration message, wherein the second CSI-RS configuration message includes information indicating a second group of beams associated with a second level of beam reporting that uses a second cycle, and wherein the first level of beam reporting differs from the second level of beam reporting,
send a first report in accordance with the first cycle, wherein the first report is based on measurement information associated with the first group, wherein the first report comprises a reference signal received power (RSRP) for a representative beam, and the representative beam is one of the beams in the first group, and
send a second report in accordance with the second cycle, wherein the second report is based on measurement information associated with the second group, wherein the second report comprises a differential RSRP associated with a RSRP for a first beam in the second group and a reference RSRP associated with a second beam in the second group.
2. The WTRU of claim 1 , wherein the reference RSRP associated with the second beam has a largest measurement value compared to RSRPs of the beams in the second group.
3. The WTRU of claim 1 , wherein the RSRP of the representative beam has a largest measurement value compared to RSRPs of the beams in the first group.
4. The WTRU of claim 1 , wherein the processor is further configured to determine the RSRP for the representative beam based on a beam reference signal, wherein the beam reference signal comprises a channel state information reference signal (CSI-RS) or a synchronization signal (SS)/physical broadcast channel (PBCH) block.
5. The WTRU of claim 1 , wherein the first report includes a channel state information (CSI) resource index associated with the representative beam.
6. The WTRU of claim 1 , wherein at least one of: (1) the first CSI-RS configuration message includes information indicating the first cycle, and/or (2) the second CSI-RS configuration message includes information indicating the second cycle.
7. The WTRU of claim 1 , wherein one or more beams in the second group are the same as one or more beams in the first group.
8. The WTRU of claim 1 , wherein the second group of beams are different than the first group of beams.
9. A method, comprising:
receiving a first channel state information reference signal (CSI-RS) configuration message, wherein the CSI-RS configuration message includes information indicating a first group of beams associated with a first level of beam reporting that uses a first cycle;
receiving a second CSI-RS configuration message, wherein the second CSI-RS configuration message includes information indicating a second group of beams associated with a second level of beam reporting that uses a second cycle, and wherein the first level of beam reporting differs from the second level of beam reporting;
sending a first report in accordance with the first cycle, wherein the first report is based on measurement information associated with the first group, wherein the first report comprises a reference signal received power (RSRP) for a representative beam, and the representative beam is one of the beams in the first group; and
sending a second report in accordance with the second cycle, wherein the second report is based on measurement information associated with the second group, wherein the second report comprises a differential RSRP associated with a RSRP for a first beam in the second group and a reference RSRP associated with a second beam in the second group.
10. The method of claim 9 , wherein the reference RSRP associated with the second beam has a largest measurement value compared to RSRPs of the beams in the second group.
11. The method of claim 9 , wherein the RSRP of the representative beam has a largest measurement value compared to RSRPs of the beams in the first group.
12. The method of claim 9 , further comprising:
determining the RSRP for the representative beam based on a beam reference signal, wherein the beam reference signal comprises a channel state information reference signal (CSI-RS) or a synchronization signal (SS)/physical broadcast channel (PBCH) block.
13. The method of claim 9 , wherein the first report includes a channel state information (CSI) resource index associated with the representative beam.
14. The method of claim 9 , wherein at least one of: (1) the first CSI-RS configuration message includes information indicating the first cycle, and/or (2) the second CSI-RS configuration message includes information indicating the second cycle.
15. The method of claim 9 , wherein one or more beams in the second group are the same as one or more beams in the first group.
16. The method of claim 9 , wherein the second group of beams are different than the first group of beams.