Method for performing beam failure detection in wireless communication system and apparatus therefor
Disclosed are a method for performing beam failure detection in a wireless communication system and an apparatus therefor. Specifically, a method for performing beam failure detection by means of a user equipment (UE) in a wireless communication system comprises the steps of: receiving a reference signal (RS) from a base station; determining whether a beam fails by measuring the reference signal; and transmitting, to the base station, the determination result on whether the beam fails, wherein by separating a case i) in which the base station does not transmit the reference signal from a case ii) in which the quality of the reference signal transmitted by the base station does not satisfy a specific threshold range, the step of determining whether the beam fails may be determined to be a beam failure only in the case ii).
1. A method of performing, by a user equipment (UE), beam failure detection in a wireless communication system, the method comprising:
receiving a reference signal (RS) from a base station;
determining whether a beam has failed based on a block error rate (BLER) calculated by performing measurement on the reference signal; and
transmitting, to the base station, a result of the determination of whether the beam has failed,
wherein determining whether the beam has failed includes:
distinguishing between i) a case where the base station does not transmit the reference signal and ii) a case where quality of the reference signal transmitted by the base station does not satisfy a specific threshold range, and
determining that the beam has failed only in the case ii),
wherein a first threshold for determining the case i) where the base station does not transmit the reference signal and a second threshold for determining the case ii) where the quality of the reference signal transmitted by the base station are separately set.
2. The method of claim 1 ,
wherein the reference signal is a reference signal triggered by downlink control information (DCI).
3. The method of claim 2 ,
wherein the reference signal triggered by the DCI corresponds to an aperiodic channel state information-RS (CSI-RS).
4. The method of claim 2 ,
wherein the result of the determination is aperiodically transmitted from a physical layer to a higher layer.
5. The method of claim 4 ,
wherein the result of the determination is transmitted based on one timing of i) a slot in which the DCI is received, ii) a slot in which the reference signal triggered by the DCI is transmitted or iii) a slot in which a PUSCH or PUCCH assigned for the report is transmitted.
6. The method of claim 1 ,
wherein when the BLER is smaller than the first threshold and greater than the second threshold, the beam failure is determined.
7. The method of claim 1 ,
wherein when the BLER is greater than the first threshold, the case i) where the base station does not transmit the reference signal is determined.
8. The method of claim 1 , further comprising receiving, from the base station, information on a determination criterion for determining whether a beam has failed.
9. The method of claim 8 ,
wherein the information on the determination criterion for determining whether a beam has failed is configured in any one unit of a band, a component carrier (CC) or a bandwidth part (BWP).
10. The method of claim 1 , further comprising receiving, from the base station, a reference signal to be used to determine whether a beam has failed among multiple downlink reference signals and/or configuration information for a determination method.
11. The method of claim 1 ,
wherein the beam failure detection is performed in an unlicensed band.
12. A user equipment (UE) performing beam failure detection in a wireless communication system, the UE comprising:
a transceiver for transmitting and receiving radio signals, and
a processor functionally connected to the transceiver,
wherein the processor is configured to:
control the transceiver to receive a reference signal (RS) from a base station,
determine whether a beam has failed based on a block error rate (BLER) calculated by performing measurement on the reference signal, and
control the transceiver to transmit, to the base station, a result of the determination of whether the beam has failed,
wherein determining whether the beam has failed includes:
distinguish between i) a case where the base station does not transmit the reference signal and ii) a case where quality of the reference signal transmitted by the base station does not satisfy a specific threshold range, and
determining that the beam has failed only in the case ii),
wherein a first threshold for determining the case i) where the base station does not transmit the reference signal and a second threshold for determining the case ii) where the quality of the reference signal transmitted by the base station are separately set.