Resource Selection in Beam Failure Recovery Transmissions
Systems, apparatuses, and methods are described for beam failure recovery in wireless communications. A plurality of candidate beams may be selected for beam failure recovery. After sending a first signal associated with a first candidate beam for beam failure recovery, the wireless device may send a second signal associated with a second candidate beam for beam failure recovery.
1 . A method comprising:
determining, based on measurement of a plurality of candidate reference signals (RSs), at least two candidate RSs of the plurality of candidate RSs;
sending, via a first random access channel (RACH) resource associated with a first candidate reference signal (RS) of the at least two candidate RSs, a first preamble for a random access procedure;
sending, via a second RACH resource associated with a second candidate RS of the at least two candidate RSs, a second preamble for the random access procedure; and
receiving, using the second candidate RS, a random access response.
2 . The method of claim 1 , further comprising:
monitoring, before the receiving the random access response and using the second candidate RS, a downlink control channel for downlink control information (DCI) scheduling the random access response.
3 . The method of claim 1 , further comprising:
determining a beam failure of a cell associated with the first candidate RS and with the second candidate RS, wherein the random access procedure is based on the determined beam failure.
4 . The method of claim 1 , wherein the determining the at least two candidate RSs comprises determining that a measurement threshold is satisfied by each of the at least two candidate RSs.
5 . The method of claim 4 , wherein the measurement threshold indicates a value associated with a measured RS received power (RSRP).
6 . The method of claim 1 , wherein the determining the at least two candidate RSs is further based on a time difference between reception of the first candidate RS and reception of the second candidate RS.
7 . The method of claim 1 , wherein the determining the at least two candidate RSs is further based on a time difference between a first transmission time interval (TTI) associated with the first candidate RS and a second TTI associated with the second candidate RS.
8 . A wireless device comprising:
one or more processors; and
memory storing instructions that, when executed by the one or more processors, configure the wireless device to:
determine, based on measurement of a plurality of candidate reference signals (RSs), at least two candidate RSs of the plurality of candidate RSs;
send, via a first random access channel (RACH) resource associated with a first candidate reference signal (RS) of the at least two candidate RSs, a first preamble for a random access procedure;
send, via a second RACH resource associated with a second candidate RS of the at least two candidate RSs, a second preamble for the random access procedure; and
receive, using the second candidate RS, a random access response.
9 . The wireless device of claim 8 , wherein the instructions, when executed by the one or more processors, further configure the wireless device to:
monitor, before the receiving the random access response and using the second candidate RS, a downlink control channel for downlink control information (DCI) scheduling the random access response.
10 . The wireless device of claim 8 , wherein the instructions, when executed by the one or more processors, further configure the wireless device to:
determine a beam failure of a cell associated with the first candidate RS and with the second candidate RS, wherein the random access procedure is based on the determined beam failure.
11 . The wireless device of claim 8 , wherein the instructions, when executed by the one or more processors, configure the wireless device to determine the at least two candidate RSs by determining that a measurement threshold is satisfied by each of the at least two candidate RSs.
12 . The wireless device of claim 11 , wherein the measurement threshold indicates a value associated with a measured RS received power (RSRP).
13 . The wireless device of claim 8 , wherein the instructions, when executed by the one or more processors, configure the wireless device to determine the at least two candidate RSs further based on a time difference between reception of the first candidate RS and reception of the second candidate RS.
14 . The wireless device of claim 8 , wherein the instructions, when executed by the one or more processors, configure the wireless device to determine the at least two candidate RSs further based on a time difference between a first transmission time interval (TTI) associated with the first candidate RS and a second TTI associated with the second candidate RS.
15 . A non-transitory computer-readable medium storing instructions that, when executed, cause:
determining, based on measurement of a plurality of candidate reference signals (RSs), at least two candidate RSs of the plurality of candidate RSs;
sending, via a first random access channel (RACH) resource associated with a first candidate reference signal (RS) of the at least two candidate RSs, a first preamble for a random access procedure;
sending, via a second RACH resource associated with a second candidate RS of the at least two candidate RSs, a second preamble for the random access procedure; and
receiving, using the second candidate RS, a random access response.
16 . The non-transitory computer-readable medium of claim 15 , wherein the instructions, when executed, further cause monitoring, before the receiving the random access response and using the second candidate RS, a downlink control channel for downlink control information (DCI) scheduling the random access response.
17 . The non-transitory computer-readable medium of claim 15 , wherein the instructions, when executed, further cause determining a beam failure of a cell associated with the first candidate RS and with the second candidate RS, and wherein the random access procedure is based on the determined beam failure.
18 . The non-transitory computer-readable medium of claim 15 , wherein the instructions, when executed, cause determining the at least two candidate RSs by determining that a measurement threshold is satisfied by each of the at least two candidate RSs.
19 . The non-transitory computer-readable medium of claim 18 , wherein the measurement threshold indicates a value associated with a measured RS received power (RSRP).
20 . The non-transitory computer-readable medium of claim 15 , wherein the instructions, when executed, cause determining the at least two candidate RSs further based on a time difference between reception of the first candidate RS and reception of the second candidate RS.