Apparatus and method for detecting control channel in wireless communication system

A user equipment (UE) in a wireless communication system, the UE comprising:

• a transceiver, and
• a controller coupled with the transceiver and configured to:
• determine a reference subcarrier spacing among a plurality subcarrier spacing,
• identify a number of serving cells with the reference subcarrier spacing,
• identify a number of serving cells for which physical downlink control channels (PDCCH)s can be detected,
• determine a sum of maximum number of detections of PDCCHs of the UE in each slot of the number of serving cells with the reference subcarrier spacing, and
• monitor PDCCH based on the sum of maximum number of detections of PDCCHs.

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

• transmitting, to a user equipment (UE), information associated with a plurality subcarrier spacing, wherein a reference subcarrier spacing is determined from among the plurality subcarrier spacing;
• and
• transmitting, to the UE, a physical downlink control channel (PDCCH),
• wherein a number of serving cell with the reference subcarrier spacing and a number of serving cells for which physical downlink control channels (PDCCHs) can be detected is identified based on the reference subcarrier spacing, and
• wherein the PDCCH is monitored based on a sum of maximum number of detections of PDCCHs of the UE in each slot of the number of serving cells with the reference subcarrier spacing.