Method and apparatus for reducing power consumption of terminal in wireless communication system

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

• transmitting, to a terminal, radio resource control (RRC) message including first information and second information, wherein the first information includes a channel state information reference signal(CSI-RS) for mobility, a discontinuous reception (DRX), and a length of DRX cycle, and wherein the second information is indicating that that the CSI-RS for mobility is transmitted even if a length of a DRX cycle is larger than or equal to a threshold;
• determining that the CSI-RS for mobility is to be transmitted outside a DRX active time in case that the terminal is configured to operate in a power saving mode and in case that the length of the DRX cycle is larger than or equal to a threshold value, based on the second information;
• transmitting, to the terminal outside a DRX active time, the CSI-RS for mobility based on the first information and the determination that the CSI-RS for mobility is to be received outside the DRX active time, wherein a preparation operation is performed based on the CSI-RS for monitoring a physical downlink control channel (PDCCH) in the DRX active time;
• and
• transmitting, to the terminal, the PDCCH in DRX occasions within the DRX active time.

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

• a transceiver configured to transmit or receive a signal;
• and
• a controller coupled with the transceiver and configured to:
• receive, from a base station, radio resource control (RRC) message including first information and second information, wherein the first information includes a channel state information reference signal (CSI-RS) for mobility, a discontinuous reception (DRX), and a length of DRX cycle, and wherein the second information is for indicating that the CSI-RS for mobility is transmitted even if a length of a DRX cycle is larger than or equal to a threshold,
• determine that the CSI-RS for mobility is to be received outside a DRX active time in case that the terminal is configured to operate in a power saving mode and in case that the length of the DRX cycle is larger than or equal to the threshold, based on the second information,
• receive, from the base station outside a DRX active time, the CSI-RS for mobility based on the first information and the determination that the CSI-RS for mobility is to be received outside the DRX active time,
• perform, by using the received CSI-RS for mobility, a preparation operation for monitoring a physical downlink control channel (PDCCH) in the DRX active time, and
• monitor the PDCCH in DRX occasions within the DRX active time based on a result of the preparation operation.

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

• a transceiver configured to transmit or receive a signal;
• and
• a controller coupled with the transceiver and configured to:
• transmit, to a terminal, radio resource control (RRC) message including first information and second information, wherein the first information includes a channel state information reference signal (CSI-RS) for mobility, a discontinuous reception (DRX), and a length of DRX cycle, and wherein the second information is indicating that that the CSI-RS for mobility is transmitted even if a length of a DRX cycle is larger than or equal to a threshold,
• determine that the CSI-RS for mobility is to be transmitted outside a DRX active time in case that the terminal is configured to operate in a power saving mode and in case that the length of the DRX cycle is larger than or equal to a threshold value, based on the second information
• transmit, to the terminal outside a DRX active time, the CSI-RS for mobility based on the first information and the determination that the CSI-RS for mobility is to be received outside the DRX active time,
• wherein a preparation operation is performed based on the CSI-RS for monitoring a physical downlink control channel (PDCCH) in the DRX active time, and
• transmit, to the terminal, the PDCCH in DRX occasions within the DRX active time.