PUCCH reset after per-TRP beam failure recovery
Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for performing beam failure recovery in scenarios involving multiple transmitter receiver points.
1 . A method for wireless communications by a user equipment (UE), comprising:
transmitting, while communicating with at least a first transmitter receiver point (TRP) associated with a first control resource set (CORESET) and a second TRP associated with a second CORESET, a beam failure recovery request (BFRQ) for the first TRP;
receiving a beam failure response (BFR) after transmitting the BFRQ; and
after receiving the BFR, transmitting physical uplink control channel (PUCCH) associated with the first TRP using a new beam indicated in the BFRQ, wherein the PUCCH associated with the first TRP is transmitted using a same closed loop power control parameter as configured or activated in spatial relation information for the PUCCH before transmitting the BFRQ.
2 . The method of claim 1 , further comprising continuing, after transmitting the BFRQ, to transmit PUCCH associated with the second TRP using a beam used prior to transmitting the BFRQ.
3 . The method of claim 1 , wherein the UE transmits the PUCCH associated with the first TRP using the new beam indicated in the BFRQ until the UE receives an activation command for updated spatial relation information for the PUCCH associated with the first TRP.
4 . The method of claim 1 , wherein the BFRQ indicates the first TRP via a CORESET pool index identifying the first CORESET.
5 . The method of claim 1 , wherein the new beam indicated in the BFRQ is associated with a beam failure detection (BFD) reference signal (RS).
6 . The method of claim 1 , further comprising providing acknowledgement feedback for downlink control information (DCI) scheduled transmissions in the first TRP and the second TRP via separate PUCCH transmissions.
7 . The method of claim 6 , wherein the BFR is conveyed via a downlink control information (DCI) format scheduling a physical uplink shared channel (PUSCH) with a same hybrid automatic repeat request (HARQ) ID as for transmission of a medium access control (MAC) control element (CE) used to convey the BFRQ.
8 . The method of claim 1 , further comprising providing joint acknowledgement feedback for downlink control information (DCI) scheduled transmissions in the first TRP and the second TRP jointly via common PUCCH transmissions.
9 . The method of claim 8 , further comprising receiving signaling scheduling a physical uplink control channel (PUCCH) to provide the joint acknowledgment feedback to the second TRP.
10 . The method of claim 1 , further comprising:
transmitting a BFRQ for the second TRP.
11 . The method of claim 1 , wherein:
the new beam indicated in the BFRQ is associated with a periodic channel state information (CSI) reference signal (CSI-RS) or synchronization signal block (SSB) or physical broadcast channel (PBCH).
12 . A method for wireless communications by a network entity, comprising:
receiving from a user equipment (UE), while the UE is communicating with at least a first transmitter receiver point (TRP) associated with a first control resource set (CORESET) and a second TRP associated with a second CORESET, a beam failure recovery request (BFRQ) for the first TRP;
transmitting a beam failure response (BFR) to the UE after receiving the BFRQ; and
after transmitting the BFR, processing physical uplink control channel (PUCCH) from the UE associated with the first TRP using a new beam indicated in the BFRQ and a same closed loop power control parameter as configured or activated in spatial relation information for the PUCCH before transmitting the BFRQ.
13 . The method of claim 12 , wherein the network entity processes the PUCCH associated with the first TRP using the new beam indicated in the BFRQ until the network entity sends an activation command for updated spatial relation information for the PUCCH associated with the first TRP.
14 . The method of claim 12 , wherein the BFRQ indicates the first TRP via a CORESET pool index identifying the first CORESET.
15 . The method of claim 12 , wherein the new beam indicated in the BFRQ is associated with a beam failure detection (BFD) reference signal (RS).
16 . The method of claim 12 , further comprising receiving acknowledgement feedback for downlink control information (DCI) scheduled transmissions in the first TRP in a PUCCH transmission separate from a PUCCH transmission with acknowledgement feedback for the second TRP.
17 . The method of claim 16 , wherein the BFR is conveyed via a downlink control information (DCI) format scheduling a physical uplink shared channel (PUSCH) with a same hybrid automatic repeat request (HARQ) ID as for transmission of a medium access control (MAC) control element (CE) used to convey the BFRQ.
18 . The method of claim 12 , further comprising receiving joint acknowledgement feedback for downlink control information (DCI) scheduled transmissions in the first TRP and the second TRP jointly via common PUCCH transmissions.
19 . The method of claim 18 , further comprising transmitting signaling scheduling a physical uplink control channel (PUCCH) to provide the joint acknowledgment feedback to the second TRP.
20 . The method of claim 12 , wherein:
the new beam indicated in the BFRQ is associated with a periodic channel state information (CSI) reference signal (CSI-RS) or synchronization signal block (SSB) or physical broadcast channel (PBCH).
21 . An apparatus for wireless communications by a user equipment, comprising:
a processing system configured to:
communicate with at least a first transmitter receiver point (TRP) associated with a first control resource set (CORESET) and a second TRP associated with a second CORESET; and
generate a beam failure recovery request (BFRQ) for the first TRP;
an interface configured to:
output, for transmission while communicating, the beam failure recovery request (BFRQ) for the first TRP;
obtain a beam failure response (BFR) after the transmission of the BFRQ; and
after the BFR was received, output, for transmission, physical uplink control channel (PUCCH) associated with the first TRP using a new beam indicated in the BFRQ, wherein the PUCCH associated with the first TRP is transmitted using a same closed loop power control parameter as configured or activated in spatial relation information for the PUCCH before transmitting the BFRQ.
22 . An apparatus for wireless communications by a network entity, comprising:
an interface configured to obtain from a user equipment (UE), while the UE is communicating with at least a first transmitter receiver point (TRP) associated with a first control resource set (CORESET) and a second TRP associated with a second CORESET, a beam failure recovery request (BFRQ) for the first TRP; and
a processing system configured to generate a beam failure response (BFR), wherein:
the interface is further configured to output, for transmission to the UE after the BFRQ was obtained, the BFR; and
after the BFR was output for transmission, the processing system is further configured to process physical uplink control channel (PUCCH) from the UE associated with the first TRP using a new beam indicated in the BFRQ, and a same closed loop power control parameter as configured or activated in spatial relation information for the PUCCH before transmitting the BFRQ.
23 . The apparatus of claim 21 , wherein the BFRQ indicates the first TRP via a CORESET pool index identifying the first CORESET.
24 . The apparatus of claim 21 , wherein the new beam indicated in the BFRQ is associated with a periodic channel state information (CSI) reference signal (CSI-RS) or synchronization signal block (SSB) or physical broadcast channel (PBCH).