CPC H04W 76/19 (2018.02) [H04B 7/0626 (2013.01); H04W 74/004 (2013.01); H04W 74/006 (2013.01)] | 9 Claims |
1. A method performed by a user equipment (UE) in a wireless communication system, the method comprising:
receiving, from a base station (BS), configuration information including a candidate beam reference signal list (candidate beam RS list) and a threshold related to a beam failure recovery;
detecting a beam failure based on a measurement of a radio link quality for one or more beam failure detection reference signals that include at least one of a Synchronization Signal Block (SSB) or a Channel State Information-Reference Signal (CSI-RS) from the candidate beam RS list;
based on detection of the beam failure, transmitting, to the BS, a beam failure recovery request,
wherein, based on i) the beam failure recovery request being transmitted based on a contention free random access resource, ii) the beam failure recovery request being related to a selected SSB or a selected CSI-RS with a radio link quality higher than the threshold from the candidate beam RS list based on the measurement, and iii) a response for the beam failure recovery request not being received within a configured time window: the beam failure recovery request is retransmitted based on a contention based random access resource after the configured time window,
wherein the response for the beam failure recovery request is a physical downlink control channel (PDCCH) related to a demodulation reference signal (DM-RS) which is quasi co-located with the selected SSB or the selected CSI-RS; and
receiving, from the BS, the response for the beam failure recovery request.
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