Default spatial relation for PUCCH and SRS with multi-TRP
Systems, devices, and methods to enable multi-TRP operation with a single DCI and with multiple DCI are described. A single DCI or multiple DCIs for the TRPs are used for PUCCH transmissions and SRS transmissions. The spatial relations between CORESET reception and PUCCH transmission or between SRS repetition are provided. The association for PUCCH transmission is dependent on whether a single spatial relation is used or multiple spatial relations are used. The association is a default association, an explicit association, and an implicit association between TRP and CORESET or TCI state.
1 . An apparatus of a transmission-reception point (TRP), the apparatus comprising:
processing circuitry configured to:
determine that a single Downlink Control Information (DCI) is to be used for multi-TRP operation, for a plurality of TRPs that includes the TRP, with a user equipment (UE);
indicate, to the UE, a number of spatial relations used for a physical uplink control channel (PUCCH) transmission from the UE;
indicate, to the UE, a spatial relation between transmission of the PUCCH and reception of a control resource set (CORESET), the spatial relation dependent on a number of spatial relations used, the spatial relation based on an association that is dependent on which of a single spatial relation is used or multiple spatial relations are used, the association selected from a default association, an explicit association, and an implicit association between TRP and at least one of the CORESET or a Transmission Configuration Indication (TCI) state; and
receive the PUCCH from the UE based on the spatial relation; and
a memory configured to store the spatial relation.
2 . The apparatus of claim 1 , wherein for the single spatial relation, the processing circuitry is configured to indicate the default association by a radio resource control (RRC) parameter enableDefaultBeamPlForPUCCH.
3 . The apparatus of claim 1 , wherein for the single spatial relation, the processing circuitry is configured to indicate the spatial relation at one of a PUCCH resource set level, a PUCCH resource group level, or a PUCCH resource level by at least one of:
a radio resource control (RRC) parameter associatedTRP-PUCCH,
a medium access control (MAC) control element (MAC-CE),
a new RRC parameter associatedTRP-PUCCH in the single DCI, or
implicit representation by a PUCCH resource group identification (ID) or PUCCH resource set ID.
4 . The apparatus of claim 1 , wherein for the single spatial relation, the processing circuitry is configured to, in response to a determination that default beam operation is enabled for PUCCH, avoid configuring the UE with spatial relations and pathloss reference signals for the PUCCH.
5 . The apparatus of claim 1 , wherein:
for the single spatial relation, each of a plurality of CORESETs is associated with a different TRP of the plurality of TRPs, a CORESET pool is defined for the single DCI multi-TRP operation, an association between each CORESET and TRP is defined by a radio resource control (RRC) parameter singleDCI-CORESETPoolIndex, and the PUCCH is associated with a particular CORESET pool via a RRC parameter associatedTRP-PUCCH, and
a default spatial relation follows one of:
a TCI state assumption of a lowest indexed CORESET among CORESETs whose configured singleDCI-CORESETPoolIndex is the same as a CORESET pool associated with the PUCCH in a latest slot in which one or more CORESETs whose configured singleDCICORESETPoolIndex is the same as the CORESET pool associated with the PUCCH are to be monitored by the UE, or
a TCI state of a scheduling CORESET.
6 . The apparatus of claim 1 , wherein for the single spatial relation, one of:
the CORESET is configured with multiple TCI states, each of the TCI states is associated with a particular TRP via a TRP identifier or each CORESET pool of a plurality of CORESET pools represents one of the TRPs, and the explicit association is between each TCI state and a corresponding CORESET pool, and the processing circuitry is configured to provide the association in a radio resource control (RRC) parameter associatedTRP-TCI in a TCI State or via a medium access control (MAC) control element (MAC-CE), or
an order of the TCI states of the CORESET indicates an association between the TCI state and the particular TRP.
7 . The apparatus of claim 1 , wherein for the single spatial relation:
the processing circuitry is configured to indicate to the UE that the PUCCH is to follow a TCI state of a particular TRP of a CORESET having a lowest index in a latest slot in which one or more CORESETs are monitored by the UE or a TCI state with a lowest TCI state identifier (ID) among TCI states of the one or more CORESETs,
association of the TCI state with the particular TRP is indicated via a radio resource control (RRC) parameter associatedTRP-TCI or via an order of the TCI state, and
the TRP associated with PUCCH is indicated by a RRC parameter associatedTRP-PUCCH or a CORESET pool associated of a scheduling CORESET is the same as the scheduling CORESET if the PUCCH is indicated by the single DCI.
8 . The apparatus of claim 1 , wherein for the single spatial relation:
at least one TCI codepoint includes multiple TCI states, and
an order of the TCI states implicitly indicates the association between the TRP and the TCI state.
9 . The apparatus of claim 1 , wherein:
for a default spatial relation of the single spatial relation to dynamically follow a particular TCI state, the processing circuitry is configured to indicate to the UE that the PUCCH is to follow the particular TCI state, among a plurality of TCI states, for physical downlink shared channel (PDSCH) reception in a latest slot in which PDSCH reception is to be performed by the UE, the particular TCI state indicated by a radio resource control (RRC) parameter associatedTRP-PUCCH or by the single DCI, or
for the single spatial relation to semi-statically follow another particular TCI state indicated by a TCI state codepoint, the processing circuitry is configured to indicate to the UE that the PUCCH is to follow one of a set of TCI states corresponding to a lowest TCI codepoint among TCI codepoints containing multiple TCI states the particular TCI state as indicated by the RRC parameter associatedTRP-PUCCH or by the single DCI.
10 . The apparatus of claim 1 , wherein:
for a TCI association, one of:
each TCI state is associated with a different TRP via a TRP identification (ID), or
each CORESET pool, of a plurality of CORESET pools, represents a different TRP, and each TCI state is associated with a different CORESET pool, and
the processing circuitry is configured to indicate the TCI association to the UE in one of:
a radio resource control (RRC) parameter associatedTRP-TCI,
a medium access control (MAC) control element (MAC-CE) to indicate the association between TCI state and TRP, or
implicit representation by an order of the TCI states to indicate the association between the TCI state and TRP if one TCI codepoint indicates multiple TCI states.
11 . The apparatus of claim 1 , wherein:
for the single spatial relation to dynamically follow a particular TCI state, the processing circuitry is configured to indicate to the UE that the PUCCH is to follow the particular TCI state, among a plurality of TCI states, for physical downlink shared channel (PDSCH) reception in a latest slot in which PDSCH reception is to be performed by the UE, the particular TCI state indicated by a radio resource control (RRC) parameter associatedTRP-TCI that has a same value as an RRC parameter associatedTRP-PUCCH or by the single DCI, or
for the single spatial relation to semi-statically follow another particular TCI state indicated by a TCI state codepoint, the processing circuitry is configured to indicate to the UE that the PUCCH is to follow one of a set of TCI states corresponding to a lowest TCI state identification (ID) among the TCI states whose RRC parameter associatedTRP-TCI has the same value as the RRC parameter associatedTRP-PUCCH or another TCI state indicated by a lowest TCI codepoint among TCI codepoints containing multiple TCI states whose RRC parameter associatedTRP-TCI has the same value as the RRC parameter associatedTRP-PUCCH.
12 . The apparatus of claim 1 , wherein at least one of:
the processing circuitry is configured to indicate to the UE that a PUCCH resource is configured with multiple spatial relations via a radio resource control (RRC) parameter enableMultipleDefaultBeam-PUCCH that, if enabled indicates spatial relations and pathloss reference signals are not configured for the PUCCH, or
each CORESET, of a plurality of CORESETs, is associated a different TRP, and the processing circuitry is configured to indicate to the UE an association between the CORESETs and TRPs via a radio resource control (RRC) parameter singleDCI-CORESETPoolIndex.
13 . The apparatus of claim 1 , wherein for the single spatial relation, the processing circuitry is configured to indicate to the UE that the PUCCH is to follow a TCI state of a CORESET having a lowest index, among CORESETs associated with a particular TRP, in a latest slot in which one or more of the CORESETs associated with the particular TRP are monitored by the UE.
14 . The apparatus of claim 1 , wherein for the single spatial relation, one of:
the CORESET is configured with multiple TCI states, each of the TCI states is associated with a particular TRP via a TRP identifier or each CORESET pool of a plurality of CORESET pools represents one of the TRPs, and the explicit association is between each TCI state and a corresponding CORESET pool, and the processing circuitry is configured to provide the association in a radio resource control (RRC) parameter associatedTRP-TCI in a TCI State or via a medium access control (MAC) control element (MAC-CE), or
an order of the TCI states of the CORESET indicates an association between the TCI state and the particular TRP.
15 . The apparatus of claim 1 , wherein for a default spatial relation, of the single spatial relation one of:
a first default spatial relation follows a first TCI state associated with a first TRP, of a lowest indexed CORESET among first CORESETs that have at least one TCI state associated with the first TRP, in a latest slot in which one or more first CORESETs are monitored by the UE, and a second default spatial relation follows a second TCI state associated with a second TRP, of a lowest indexed CORESET among second CORESETs that have at least one TCI state associated with the second TRP, in a latest slot in which one or more second CORESETs are monitored by the UE,
the default spatial relation sequentially follows a TCI state associated with a lowest indexed CORESET among third CORESETs that have multiple TCI states associated with different TRPs, in a latest slot in which one or more third CORESETs are monitored by the UE, or
the default spatial relation sequentially follows TCI states of a scheduling CORESET, if the scheduling CORESET is configured with multiple active TCI states.
16 . The apparatus of claim 1 , wherein for the single spatial relation if at least one TCI codepoint indicates multiple TCI states, one of:
multiple default spatial relations dynamically follow TCI states of a physical downlink shared channel (PDSCH), the default spatial relations of PUCCH sequentially follow the TCI states for PDSCH reception in a latest slot in which the PDSCH is received with multiple TCI states indicated by one of the at least one TCI codepoint,
the multiple default spatial relations semi-statically follow TCI states corresponding to a lowest TCI codepoint among TCI codepoints containing multiple TCI states that are activated for the PDSCH, or
the multiple default spatial relations are semi-statically and independently derived, if the TCI states of the PDSCH are explicitly associated with a TRP, then first default spatial relations of the PUCCH follow a TCI state with a first lowest TCI state identifier (ID) among TCI states associated with a first TRP and second default spatial relations of the PUCCH follow a TCI state with a second lowest TCI state ID among TCI states associated with a second TRP.
17 . A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors of transmission-reception point (TRP), the one or more processors to configure the TRP to, when the instructions are executed:
determine that a single Downlink Control Information (DCI) is to be used for multi-TRP operation, for a plurality of TRPs that includes the TRP, with a user equipment (UE);
indicate, to the UE, a number of spatial relations used for a from the UE;
indicate, to the UE, a spatial relation between transmission of a physical uplink control channel (PUCCH) and reception of a control resource set (CORESET), the spatial relation dependent on a number of spatial relations used, the spatial relation based on an association that is dependent on which of a single spatial relation is used or multiple spatial relations are used, the association selected from a default association, an explicit association, and an implicit association between TRP and at least one of a control resource set (CORESET) or a Transmission Configuration Indication (TCI) state; and
receive the PUCCH from the UE based on the spatial relation.
18 . The medium of claim 17 , wherein:
for the single spatial relation, each of a plurality of CORESETs is associated with a different TRP of the plurality of TRPs, a CORESET pool is defined for the single DCI multi-TRP operation, an association between each CORESET and TRP is defined by a radio resource control (RRC) parameter singleDCI-CORESETPoolIndex, and the PUCCH is associated with a particular CORESET pool via a RRC parameter associatedTRP-PUCCH, and
a default spatial relation follows one of:
a TCI state assumption of a lowest indexed CORESET among CORESETs whose configured singleDCI-CORESETPoolIndex is the same as a CORESET pool associated with the PUCCH in a latest slot in which one or more CORESETs whose configured singleDCICORESETPoolIndex is the same as the CORESET pool associated with the PUCCH are to be monitored by the UE, or
a TCI state of a scheduling CORESET.
19 . An apparatus of a user equipment (UE), the apparatus comprising:
processing circuitry configured to:
receive, from a transmission-reception point (TRP), an indication that a single Downlink Control Information (DCI) is to be used for multi-TRP operation, for a plurality of TRPs that includes the TRP;
receive, from the TRP, an indication of a number of spatial relations used for a physical uplink control channel (PUCCH) transmission from the UE;
receive, from the TRP, an indication of a spatial relation between transmission of the PUCCH and reception of a control resource set (CORESET), the spatial relation dependent on the number of spatial relations used, the spatial relation based on an association that is dependent on whether a single spatial relation is used or multiple spatial relations are used, the association selected from a default association, an explicit association, and an implicit association between TRP and at least one of the CORESET or a Transmission Configuration Indication (TCI) state; and
transmit the PUCCH to the TRP based on the indicated spatial relation; and
a memory configured to store the spatial relation.
20 . The apparatus of claim 19 , wherein:
for the single spatial relation, each of a plurality of CORESETs is associated with a different TRP of the plurality of TRPs, a CORESET pool is defined for the single DCI multi-TRP operation, an association between each CORESET and TRP is defined by a radio resource control (RRC) parameter singleDCI-CORESETPoolIndex, and the PUCCH is associated with a particular CORESET pool via a RRC parameter associatedTRP-PUCCH, and
a default spatial relation follows one of:
a TCI state assumption of a lowest indexed CORESET among CORESETs whose configured singleDCI-CORESETPoolIndex is the same as a CORESET pool associated with the PUCCH in a latest slot in which one or more CORESETs whose configured singleDCICORESETPoolIndex is the same as the CORESET pool associated with the PUCCH are to be monitored by the UE, or
a TCI state of a scheduling CORESET.