Channel state information reporting on licensed and unlicensed carriers

A user equipment for reporting channel state information (CSI) to a base station in a communication system in which a plurality of downlink component carriers and at least one uplink component carrier are configured, the user equipment comprising:

• a receiver, which, in operation, receives from the base station, in a slot nTrigger, a trigger message that triggers reporting of the CSI for at least one unlicensed downlink component carrier of the plurality of downlink component carriers;
• and
• a transmitter, which, in operation, transmits to the base station, in a slot nReport later than nTrigger, the CSI for the at least one unlicensed downlink component carrier based on reference signals present, in a slot nRS indicated by the base station, on the at least one unlicensed downlink component carrier,
• wherein,
• responsive to the at least one unlicensed downlink component carrier being occupied for a period of time for a bursty downlink transmission between the base station and the user equipment, only the reference signals in the slot nRS are evaluated for the CSI, and other slots in the period of time for the bursty downlink transmission are not evaluated for the CSI.