A User Equipment (UE) to transmit Hybrid Automatic Repeat Request-Acknowledgment (HARQ-ACK), the UE comprising:
- a controller to set N pieces of HARQ-ACK to Discontinuous Transmission (DTX) for a cell, based on a difference between KPCell and KSCell, the difference being associated with the number N, and to generate the HARQ-ACK comprising the N pieces of HARQ-ACK set to DTX, the HARQ-ACK being responsive to data received from a base station (BS), the number N being an integer greater than one;
- and
- a transmitter to transmit, to the BS, the response,
- wherein the KPCell is a number of downlink subframe(s) of a Primary Cell (PCell) associated with an uplink subframe and the KSCell is a number of downlink subframe(s) of a Secondary Cell (SCell) associated with the uplink subframe.