Beam failure detection using shared reference signals
Apparatuses, methods, and systems are disclosed for shared beam failure detection (BFD) and recovery. One apparatus includes a transceiver that receives a configuration from a radio access network (RAN) for a set of shared BFD reference signals (RS), where the set of shared BFD RS is quasi-co-located with a set of shared user equipment (UE) receive beams applicable to a group of UEs. The processor measures a signal strength on the set of shared BFD RS, increments a shared beam failure instance (BFI) counter if the measured signal strength is below a BFD RS threshold value, and also increments the shared BFI upon receiving a BFI indication from a UE in the group of UEs. The processor declares BFD for the group of UEs in response to the shared BFI counter reaching a maximum value of beam failure.
1 . A user equipment (“UE”) for wireless communication, comprising:
a memory; and
a processor coupled with the memory and configured to cause the UE to:
receive a configuration from a radio access network (“RAN”) for multiple sets of beam failure detection (“BFD”) reference signals (“RS”), including a set of shared BFD RS, wherein the set of shared BFD RS is quasi-co-located with a set of shared UE receive (“Rx”) beams applicable to a group of UEs, and wherein the configuration further comprises multiple Beam Failure Instance (“BFI”) counters including a shared BFI counter, and an association of at least one BFD RS set and a corresponding BFI counter to one of a plurality of RS groups;
measure a signal strength on one or more of the multiple sets of BFD RS, including the set of shared BFD RS;
increment the shared BFI counter by one in response to the measured signal strength associated with the set of shared BFD RS satisfying a BFD RS threshold value;
increment the shared BFI counter by one in response to receiving a BFI indication from a UE in the group of UEs; and
declare BFD for the group of UEs in response to the shared BFI counter reaching a maximum value of beam failure.
2 . The UE of claim 1 , wherein to declare BFD, wherein the processor is configured to cause the UE to initiate a random-access procedure via a medium access control (“MAC”) layer in response to the shared BFI counter reaching a maximum value of beam failure.
3 . The UE of claim 1 , wherein the processor is configured to cause the UE to transmit a second BFI indication to all UEs in the group of UEs in response to the measured signal strength being below the BFD RS threshold value.
4 . The UE of claim 3 , wherein to transmit the second BFI indication to all UEs, wherein the processor is configured to cause the UE to transmit the second BFI indication via sidelink unicast messaging, sidelink groupcast messaging, or combinations thereof.
5 . The UE of claim 1 , wherein the configuration for the set of shared BFD RS comprises an indication that the UE is configured as a primary UE within the group of UEs, wherein the primary UE declares BFD for itself and at least one second UE belonging to the group of UEs, wherein the primary UE initiates beam failure recovery for itself and the at least one second UE.
6 . The UE method of claim 5 , wherein the at least one second UE is configured as secondary UE that signals the BFI indication to the group of UEs configured with the set of shared UE Rx beams, but does not declare BFD for itself or any other UE belonging to the group of UEs.
7 . The UE of claim 1 , wherein the configuration for the set of shared BFD RS indicates the BFD RS threshold value and the maximum value of beam failure.
8 . The UE of claim 1 , wherein the processor is configured to cause the UE to declare BFD for the group of UEs in response to a respective BFI counter reaching a maximum value of beam failure counter for each RS group comprising a shared BFD RS.
9 . The UE of claim 8 , wherein the processor is configured to cause the UE to declare a UE-specific BFD in response to the respective BFI counter reaching a maximum value of beam failure counter for each RS group comprising a non-shared BFD RS.
10 . A method performed by a user equipment (“UE”), the method comprising:
a memory; and
a processor coupled with the memory and configured to cause the UE to:
receiving a configuration from a radio access network (“RAN”) for multiple sets of beam failure detection (“BFD”) reference signals (“RS”), including a set of shared BFD RS, wherein the set of shared BFD RS is quasi-co-located with a set of shared UE receive (“Rx”) beams applicable to a group of UEs, and wherein the configuration further comprises multiple Beam Failure Instance (“BFI”) counters including a shared BFI counter, and an association of at least one BFD RS set and a corresponding BFI counter to one of a plurality of RS groups;
measuring a signal strength on one or more of the multiple sets of BFD RS, including the set of shared BFD RS;
incrementing the shared BFI counter by one in response to the measured signal strength associated with the set of shared BFD RS satisfying a BFD RS threshold value;
incrementing the shared BFI counter by one in response to receiving a BFI indication from a UE in the group of UEs; and
declaring BFD for the group of UEs in response to the shared BFI counter reaching a maximum value of beam failure.
11 . A base station for wireless communication, comprising:
a memory; and
a processor coupled with the memory and configured to cause the base station to:
transmit, to a user equipment (“UE”), a first configuration for multiple sets a set of shared beam failure detection (“BFD”) reference signals (“BFD-RS”), including of BFD RS, wherein the set of shared BFD RS is quasi-co-located with a set of shared UE receive (“Rx”) beams applicable to a group of UEs, and wherein the first configuration further comprises multiple Beam Failure Instance (“BFI”) counters including a shared BFI counter, and an association of at least one BFD RS set and a corresponding BFI counter to one of a plurality of RS groups;
transmit one or more shared BFD RS;
receive a BFD indication from the UE for group of UEs; and
transmit a second configuration to the group of UEs in response to the BFD indication, wherein the second configuration comprises new candidate beams.
12 . The base station of claim 11 , wherein the first configuration configures the UE as a primary UE, wherein the primary UE declares BFD for itself and at least one second UE belonging to the group of UEs, wherein the primary UE initiates beam failure recovery for itself and the at least one second UE.
13 . The base station of claim 11 , wherein the first configuration configures the UE as a secondary UE, wherein the first configuration comprises an instruction to transmit a BFI indication to the group of UEs configured with the set of shared UE Rx beams, and an instruction to forgo declaring but does not declare BFD for the secondary UE or any other UE belonging to the group of UEs.
14 . The base station of claim 11 , wherein the first configuration indicates a BFD RS threshold value and a maximum value of beam failure.
15 . A method performed by a base station, the method comprising:
transmitting, to a user equipment (“UE”), a first configuration for multiple sets of beam failure detection (“BFD”) reference signals (“RS”), including a set of shared BFD RS, wherein the set of shared BFD RS is quasi-co-located with a set of shared UE receive (“Rx”) beams applicable to a group of UEs, and wherein the first configuration further comprises multiple Beam Failure Instance (“BFI”) counters including a shared BFI counter, and an association of at least one BFD RS set and a corresponding BFI counter to one of a plurality of RS groups;
transmitting one or more shared BFD RS;
receiving a BFD indication from the UE for group of UEs; and
transmitting a second configuration to the group of UEs in response to the BFD indication, wherein the second configuration comprises new candidate beams.
16 . The method of claim 15 , wherein the first configuration configures the UE as a primary UE, wherein the primary UE declares BFD for itself and at least one second UE belonging to the group of UEs, wherein the primary UE initiates beam failure recovery for itself and the at least one second UE.
17 . The method of claim 15 , wherein the first configuration configures the UE as a secondary UE, wherein the first configuration comprises an instruction to transmit a BFI indication to the group of UEs configured with the set of shared UE Rx beams, and an instruction to forgo declaring but does not declare BFD for the secondary UE or any other UE belonging to the group of UEs.
18 . The method of claim 15 , wherein the first configuration indicates a BFD RS threshold value and a maximum value of beam failure.
19 . The method of claim 10 , wherein the configuration for the set of shared BFD RS comprises an indication that the UE is configured as a primary UE within the group of UEs, wherein the primary UE is configured to declare BFD for itself and at least one second UE belonging to the group of UEs, and wherein the primary UE is configured to initiate beam failure recovery for itself and the at least one second UE.
20 . The method of claim 10 , wherein declaring BFD for the group of UEs occurs in response to a respective BFI counter reaching a maximum value of beam failure counter for each RS group comprising a shared BFD RS, the method further comprising:
declaring a UE-specific BFD in response to the respective BFI counter reaching a maximum value of beam failure counter for each RS group comprising a non-shared BFD RS.