The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The present invention provides a method performed by a terminal comprising, transmitting, to a base station, an uplink signal, identifying hybrid automatic repeat request (HARQ) related information corresponding to the uplink signal, and adjusting a contention window (CW) for performing an LBT mechanism based on the identified HARQ related information. According to the method provided by the present disclosure, the flexibility that the base station controls the LBT mechanism of the uplink transmission of the UE can be improved, the waste of uplink resources and downlink resources can be avoided, and coexistence with another device can be ensured.