	US 12,483,315 B2
	Beam failure recovery method of base station in wireless communication system using RIS, apparatus therefor, and program therefor
Wan Choi, Seoul (KR); Jin Kyu Lee, Seoul (KR); and Kwang Jae Lee, Seoul (KR)
Assigned to Seoul National University R&DB Foundation, Seoul (KR)
Filed by SEOUL NATIONAL UNIVERSITY R&DB FOUNDATION, Seoul (KR)
Filed on Nov. 14, 2023, as Appl. No. 18/509,237.
Claims priority of application No. 10-2022-0151473 (KR), filed on Nov. 14, 2022.
Prior Publication US 2024/0162968 A1, May 16, 2024
Int. Cl. H04B 7/06 (2006.01); H04B 17/318 (2015.01)

CPC H04B 7/06964 (2023.05) [H04B 17/328 (2023.05)]

11 Claims

1. A beam failure recovery method of a base station (BS) in a wireless communication system using a reconfigurable intelligent surface (RIS), the beam failure recovery method comprising:

configuring a candidate beam set, based on a measured reference signal received power (RSRP) value in beam sweeping using an antenna;

establishing a communication link with a user equipment (UE) through a main beam having the measured RSRP value exceeding a predetermined threshold in the configured candidate beam set;

selecting a beam, based on the measured RSRP value, from a synchronization signal block (SSB) to which the main beam belongs and an SSB to which the main beam does not belong when beam failure occurs in the established communication link; and

recovering the beam failure with the UE through the selected beam,

wherein the configuring of the candidate beam set comprises comprising a plurality of beams included in a direct path to the UE and a reflective path through the RIS in the candidate beam set, and

wherein the beam failure recovery method further comprises, before the selecting of the beam,

obtaining measured values of an angle of arrival (AoA), an angle of departure (AoD), and a time of arrival (ToA) corresponding to each beam of the candidate beam set; and

corresponding each beam to the direct path or the reflective path, based on the obtained measured values.