1. A method for transmitting Hybrid Automatic Repeat Request-Acknowledgment (HARQ-ACK) signal by a user equipment (UE) in a wireless communication system supporting a plurality of transmission time interval (TTI) lengths, the method comprising:receiving downlink data; and
transmitting a HARQ-ACK signal related to the downlink data,
wherein the HARQ-ACK signal is transmitted after a processing time from receiving the downlink data,
wherein, based on a downlink TTI length for the downlink data and an uplink TTI length for the HARQ-ACK signal being different;
the processing time is configured in units of at least one of the downlink TTI length and the uplink TTI length, and
based on a first transmission timing of an uplink control channel for HARQ-ACK signal and a second transmission timing of a 2-symbol short Physical Uplink Shared Channel (sPUSCH) overlapping;
based on the downlink TTI length being shorter than a predetermined length, the uplink control channel is transmitted and the 2-symbol sPUSCH is dropped, and
based on the downlink TTI length being equal to or longer than the predetermined length, the uplink control channel is dropped, the 2-symbol sPUSCH is transmitted and uplink control information (UCI) for the uplink control channel is piggybacked to the 2-symbol sPUSCH.