Method and device for transmitting and receiving signal in wireless communication system

A terminal in a wireless communication system, the terminal comprising:

• a transceiver;
• and
• a processor coupled to the transceiver,
• wherein the processor is configured to:
• receive, from a base station, at least one reference signal,
• perform a measurement based on the at least one reference signal,
• generate a measurement report related to channel state information based on the measurement, and
• transmit, to the base station, the measurement report,
• wherein the at least one reference signal is transmitted from the base station to the terminal through a reconfigurable intelligent surface (RIS), and
• wherein first beamforming, controlled by the base station at RIS is determined based on the measurement report;
• wherein the terminal transmits a first RIS use request signal to the RIS before receiving the at least one reference signal,
• the RIS operates in an initial recognition mode based on the first RIS use request signal, and
• wherein the initial recognition mode is determined based on a number of sub-arrays and a minimum number of beams related to at least one meta lens element in the RIS;
• wherein the initial recognition mode is determined based on the number of sub-arrays and the minimum number of beams that satisfy a frequency rate direction constant derived based on frequency rate learning information related to a terminal direction,
• wherein the number of sub-arrays is set to 1, in case that there is no combination of the number of sub-arrays and the minimum number of beams that satisfies the frequency rate direction constant, and wherein, based on the number of sub-arrays being 1, the RIS generates a fixed spherical wave.

A base station in a wireless communication system, the base station comprising:

• a transceiver;
• and
• a processor coupled to the transceiver,
• wherein the processor is configured to:
• transmit, to a terminal, at least one reference signal, and
• receive a measurement report related to channel state information based on a measurement performed by the terminal that received the at least one reference signal,
• wherein the at least one reference signal is transmitted from the base station to the terminal through a reconfigurable intelligence surface (RIS),
• wherein first beamforming, controlled by the base station to, at RIS is determined based on the measurement report;
• wherein the terminal transmits a first RIS use request signal to the RIS before receiving the at least one reference signal,
• the RIS operates in an initial recognition mode based on the first RIS use request signal, and
• wherein the initial recognition mode is determined based on a number of sub-arrays and a minimum number of beams related to at least one meta lens element in the RIS;
• wherein the initial recognition mode is determined based on the number of sub-arrays and the minimum number of beams that satisfy a frequency rate direction constant derived based on frequency rate learning information related to a terminal direction,
• wherein the number of sub-arrays is set to 1, in case that there is no combination of the number of sub-arrays and the minimum number of beams that satisfies the frequency rate direction constant, and wherein, based on the number of sub-arrays being 1, the RIS generates a fixed spherical wave.