Beam management enhancements
Beam management for the downlink can be based on user equipment (UE) measurement of downlink (DL) reference signal (RS) and UE reporting. An alternative approach that may reduce overall RS overhead and latency is BM for the downlink based on uplink (UL) RS. With this approach, the network measures UL RS transmissions on multiple beams and uses these measurements for managing beams for the DL. Disclosed herein are various problems and enhancements related to UL RS based DL BM, in particular beam failure detection and recovery.
1 . A method comprising:
receiving configuration information, wherein the configuration information indicates a control resource set (CORESET) has a first quasi co-location (QCL) relationship of a first type with a downlink (DL) reference signal (RS);
receiving an activation indication, wherein the activation indication indicates a second an uplink (UL) RS has a second QCL relationship of a second type with the CORESET and with the DL RS;
receiving the DL RS based on the second QCL relationship with the second UL RS; and
based on the first QCL relationship with the DL RS and the second QCL relationship with the UL RS, receiving a physical downlink control channel (PDCCH) using the CORESET.
2 . The method of claim 1 , wherein the activation indication further indicates a second DL RS has a third QCL relationship of a third type with the DL RS.
3 . The method of claim 2 , further comprising receiving the DL RS based on the third QCL relationship with the second DL RS.
4 . The method of claim 2 , wherein:
the second DL RS comprises a synchronization signal block (SSB); and
the third QCL relationship comprises QCL-Type C.
5 . The method of claim 1 , wherein the CORESET comprises a demodulation reference signal (DMRS).
6 . The method of claim 1 , wherein the first QCL relationship comprises QCL-TypeA.
7 . The method of claim 1 , wherein the DL RS comprises a tracking RS (TRS).
8 . The method of claim 1 , wherein the UL RS comprises a UL sounding RS (SRS).
9 . The method of claim 1 , wherein the second QCL relationship comprises QCL-TypeD.
10 . A wireless transmit/receive unit (WTRU) comprising:
a processor; and
memory coupled with the processor, the memory comprising executable instructions stored thereon that when executed by the processor cause the processor to effectuate operations comprising:
receiving configuration information, wherein the configuration information indicates a control resource set (CORESET) has a first quasi co-location (QCL) relationship of a first type with a downlink (DL) reference signal (RS);
receiving an activation indication, wherein the activation indication indicates a second an uplink (UL) RS has a second QCL relationship of a second type with the CORESET and with the DL RS;
receiving the DL RS based on the second QCL relationship with the UL RS; and
based on the first QCL relationship with the DL RS and the second QCL relationship with the UL RS, receiving a physical downlink control channel (PDCCH) using the CORESET.
11 . The WTRU of claim 10 , wherein the activation indication further indicates a second DL RS has a third QCL relationship of a third type with the DL RS.
12 . The WTRU of claim 11 , the operations further comprising receiving the DL RS based on the third QCL relationship with the second DL RS.
13 . The WTRU of claim 11 , wherein:
the second DL RS comprises a synchronization signal block (SSB); and
the third QCL relationship comprises QCL-Type C.
14 . The WTRU of claim 10 , wherein the CORESET comprises a demodulation RS (DMRS).
15 . The WTRU of claim 10 , wherein the first QCL relationship comprises QCL-TypeA.
16 . The WTRU of claim 10 , wherein the DL RS comprises a tracking RS (TRS).
17 . The WTRU of claim 10 , wherein the UL RS comprises a UL sounding RS (SRS).
18 . The WTRU of claim 10 , wherein the second QCL relationship comprises QCL-TypeD.
19 . An apparatus comprising:
a processor; and
memory coupled with the processor, the memory comprising executable instructions stored thereon that when executed by the processor cause the processor to effectuate operations comprising:
sending configuration information, wherein the configuration information indicates a control resource set (CORESET) has a first quasi co-location (QCL) relationship of a first type with a downlink (DL) reference signal (RS);
sending an activation indication, wherein the activation indication indicates an uplink (UL) RS has a second QCL relationship of a second type with the CORESET and with the DL RS;
sending the DL RS based on the second QCL relationship with the UL RS; and
based on the first QCL relationship with the DL RS and the second QCL relationship with the UL RS, sending a physical downlink control channel (PDCCH) using the CORESET.
20 . The apparatus of claim 19 , wherein the activation indication further indicates a second DL RS has a third QCL relationship of a third type with the DL RS.