MAC CE based common beam indication
Methods and apparatuses for MAC CE based common beam indication are disclosed. In one embodiment, a method comprises receiving a higher layer parameter to enable MAC CE based common beam indication; receiving a common beam indication MAC CE; and determining a common beam according to the common beam indication MAC CE.
1 . A user equipment (UE) for wireless communications, comprising:
at least one memory; and
at least one processor coupled with the at least one memory and operable to cause the UE to:
receive medium access control (MAC) control element (CE) that indicates a common downlink beam for reception of physical downlink control channel (PDCCH) transmissions and physical downlink shared channel (PDSCH) transmissions, wherein the MAC CE indicates a transmission configuration indicator (TCI) state for both downlink reception and uplink transmission;
determine, based at least in part on the TCI state, the common downlink beam for the reception of the PDCCH transmissions and the PDSCH transmissions; and
determine, based at least in part on a quasi-colocation (QCL)-TypeD reference signal associated with the TCI state and a pathloss-reference signal (PL-RS) associated with the TCI state, a common uplink beam for transmission of physical uplink control channel (PUCCH) transmissions and physical uplink shared channel (PUSCH transmissions.
2 . The UE of claim 1 , wherein the MAC CE comprises a TCI field that indicates the TCI state, and wherein the UE has at least one of a joint downlink and uplink beam indication capability or a separate downlink and uplink beam indication capability according to the TCI state.
3 . The UE of claim 2 , wherein the TCI state applies to the reception of the PDCCH transmissions and the PDSCH transmissions in one or more bandwidth parts (BWPs) in a cell indicated by the MAC CE.
4 . The UE of claim 2 , wherein the QCL-TypeD reference signal is determined as a spatial relation and the PL-RS for the transmission of the PUCCH transmissions and the PUSCH transmissions in one or more band width parts (BWPs) in a cell indicated by the MAC CE, wherein the UE has the joint downlink and uplink beam indication capability.
5 . The UE of claim 2 , wherein a higher layer parameter CORESETPoolIndex is configured for one or more respective control resource sets (CORESETs), wherein the TCI state applies to reception of the PDCCH transmissions from one or more CORESETs configured with a same CORESETPoolIndex as that configured for a CORESET indicated by the MAC CE, and wherein the TCI state applies to reception of the PDSCH transmissions scheduled by at least one downlink control information (DCI) transmitted from the CORESETs configured with the same CORESETPoolIndex as that configured for the CORESET indicated by the MAC CE.
6 . The apparatus UE of claim 2 , wherein the PUCCH transmissions and the PUSCH transmissions are associated with a same CORESETPoolIndex as that configured for a CORESET indicated by the MAC CE.
7 . The UE of claim 1 , wherein the MAC CE indicates spatial relation information, and wherein the common uplink beam is determined based at least in part on the UE having a separate downlink and uplink beam indication capability according to the spatial relation information.
8 . The UE of claim 7 , wherein the PL-RS comprises a spatial relation associated with the spatial relation information, and wherein the PUCCH transmissions and the PUSCH transmissions are in one or more band width parts (BWPs) in a cell indicated by the MAC CE based at least in part on a CORESETPoolIndex not being configured for a CORESET in the cell indicated by the MAC CE.
9 . The UE of claim 7 , wherein the PL-RS comprises a spatial relation associated with first spatial relation information for one or more first PUCCH transmissions associated with CORESETPoolIndex=0 and one or more first PUSCH transmissions scheduled by at least one first downlink control information (DCI) transmitted from one or more first control resource sets (CORESETs) configured with CORESETPoolIndex=0 in one or more first band width parts (BWPs) in a cell indicated by the MAC CE, and wherein the spatial relation is associated with second spatial relation information for one or more second PUCCH transmissions associated with CORESETPoolIndex=1 and one or more second PUSCH transmissions scheduled by at least one second DCI transmitted from one or more second CORESETs with CORESETPoolIndex=1 in one or more second BWPs in the cell indicated by the MAC CE based at least in part on a CORESETPoolIndex being configured for the one or more second CORESETs in the cell indicated by the MAC CE.
10 . The UE of claim 7 , wherein a higher layer parameter CORESETPoolIndex is configured for one or more respective control resource sets (CORESETs), and wherein the PL-RS comprises a spatial relation associated with the spatial relation information for one or more PUCCH transmissions associated with a same first CORESETPoolIndex and one or more PUSCH transmissions scheduled by at least one downlink control information (DCI) transmitted from one or more CORESETs configured with a same second CORESETPoolIndex as that associated with a PUCCH resource indicated in the MAC CE in one or more band width parts (BWPs) in a cell indicated by the MAC CE.
11 . The UE of claim 1 , wherein the at least one processor is further operable to cause the UE to:
receive a configuration of one or more cell lists comprising one or more respective serving cells, wherein the common uplink beam is enabled for the one or more respective serving cells in a cell list of the one or more cell lists comprising a serving cell, and wherein the MAC CE indicates the serving cell.
12 . The apparatus UE of claim 11 , wherein the MAC CE comprises a TCI field that indicates the TCI state, and wherein the TCI state applies to the PDCCH transmissions, the PDSCH transmission, the PUCCH transmissions, and the PUSCH transmissions in one or more band width parts (BWPs) in cells belonging to the cell list.
13 . The UE of claim 11 , wherein the MAC CE indicates a spatial relation information, and wherein the indicated spatial relation information applies to the transmission of the PUCCH transmissions and the PUSCH transmissions in one or more band width parts (BWPs) in cells belonging to the cell list.
14 . A method performed by a user equipment (UE), the method comprising:
receiving a medium access control (MAC) control element (CE) that indicates a common downlink beam for reception of physical downlink control channel (PDCCH) transmissions and physical downlink shared channel (PDSCH) transmissions, wherein the MAC CE indicates a transmission configuration indicator (TCI) state for both downlink reception and uplink transmission;
determining, based at least in part on the TCI state, the common downlink beam for the reception of the PDCCH transmissions and the PDSCH transmissions; and
determining, based at least in part on a quasi-colocation (QCL)-TypeD reference signal associated with the TCI state and a pathloss-reference signal (PL-RS) associated with the TCI state, a common uplink beam for transmission of physical uplink control channel (PUCCH) transmissions and physical uplink shared channel (PUSCH) transmissions.
15 . The method of claim 14 , wherein the MAC CE comprises a TCI field that indicates the TCI state, and wherein the UE has at least one of joint downlink and uplink beam indication capability or separate downlink and uplink beam indication capability according to the TCI state.
16 . The method of claim 14 , wherein the MAC CE indicates spatial relation information, and wherein the common uplink beam is determined based at least in part on the UE having a separate downlink and uplink beam indication capability according to the spatial relation information.
17 . The method of claim 14 , further comprising:
receiving a configuration of one or more cell lists comprising one or more respective serving cells, wherein the common uplink beam is enabled for the one or more respective serving cells in a cell list of the one or more cell lists comprising a serving cell, and wherein the MAC CE indicates the serving cell.
18 . The method of claim 17 , wherein the MAC CE comprises a TCI field that indicates the TCI state, and wherein the TCI state applies to the PDCCH transmissions, the PDSCH transmissions, the PUCCH transmissions, and the PUSCH transmissions in one or more band width parts (BWPs) in cells belonging to the cell list.
19 . A network equipment (NE) for wireless communications, comprising:
at least one memory; and
at least one processor coupled with the at least one memory and operable to cause the NE to:
transmit a medium access control (MAC) control element (CE) that indicates a common downlink beam for reception of physical downlink control channel (PDCCH) transmissions and physical downlink shared channel (PDSCH) transmissions at a user equipment (UE), wherein the MAC CE indicates a transmission configuration indicator (TCI) state for both downlink reception and uplink transmission;
determine, based at least in part on the TCI state, the common downlink beam for the reception of the PDCCH transmissions and the PDSCH transmissions; and
determine, based at least in part on a quasi-colocation (QCL)-TypeD reference signal associated with the TCI state and a pathloss-reference signal (PL-RS) associated with the TCI state, a common uplink beam for transmission of physical uplink control channel (PUCCH) transmissions and physical uplink shared channel (PUSCH) transmissions at the UE.
20 . A method performed by a network equipment (NE), the method comprising:
transmitting a medium access control (MAC) control element (CE) that indicates a common downlink beam for reception of physical downlink control channel (PDCCH) transmissions and physical downlink shared channel (PDSCH) transmissions at a user equipment (UE), wherein the MAC CE indicates a transmission configuration indicator (TCI) state for both downlink reception and uplink transmission;
determining, based at least in part on the TCI state, the common downlink beam for the reception of the PDCCH transmissions and the PDSCH transmissions; and
determining, based at least in part on a quasi-colocation (QCL)-TypeD reference signal associated with the TCI state and a pathloss-reference signal (PL-RS) associated with the TCI state, a common uplink beam for transmission of physical uplink control channel (PUCCH) transmissions and physical uplink shared channel (PUSCH) transmissions at the UE.