1. A method of transmitting an uplink signal, by a user equipment (UE), in a wireless communication system, the method comprising:reporting, to a base station (BS), capability information, wherein the capability information comprises information related to the simultaneous transmission capability of the uplink signal for different transmission time interval (TTI) lengths;
receiving a downlink data channel in at least one serving cell based on the capability information; and
transmitting a first uplink control channel for the downlink data channel,
wherein a cell for carrying the first uplink control channel is a primary cell of an uplink control channel group to which the at least one serving cell belongs, and
wherein the primary cell for carrying the first uplink control channel is configured to support a short TTI (sTTI)-based operation based on the sTTI-based operation being configured for the at least one serving cell.