Method and device for multi-group multicasting in wireless communication system

A method for operating a base station, the method comprising:

• transmitting, to at least one user equipment (UE), at least one reference signal;
• receiving, from the at least one UE, feedback information based on the at least one reference signal;
• and
• transmitting, to the at least one UE, downlink data,
• wherein the downlink data is transmitted based on a spatial domain transmission filter, and received by the at least one UE after being reflected by a first Reconfigurable Intelligent Surface (RIS) among a plurality of RISs,
• wherein each of the plurality of RISs assists signal transmission of each of a plurality of groups including a plurality of UEs.

A user equipment (UE) comprising:

• a transceiver;
• and
• a processor connected to the transceiver,
• wherein the processor is configured to perform operations comprising:
• receiving, from a base station, at least one reference signal;
• transmitting, to the base station, feedback information based on the at least one reference signal;
• and
• receiving, from the base station, downlink data,
• wherein the downlink data is transmitted based on a spatial domain transmission filter, and received by the UE after being reflected by a first Reconfigurable Intelligent Surface (RIS) among a plurality of RISs,
• wherein each of the plurality of RISs assists signal transmission of each of a plurality of groups including a plurality of UEs.