A method of transmitting and receiving a signal by a user equipment configured with a plurality of cells, the method comprising: performing blind decoding of scheduling information in a first uplink subframe of a first cell with a time division duplex, TDD, frame structure among the plurality of cells, by assuming the first uplink subframe as a downlink subframe when the first uplink subframe is a flexible uplink subframe; receiving downlink data via a second cell on an unlicensed band among the plurality of cells when the scheduling information including a downlink grant for the second cell is detected by the blind decoding; and transmitting, via the second cell, uplink control information piggy backed from the first cell, wherein modulation and coding scheme, MCS, information that is different from MCS information of the first cell is applied to the piggy backed uplink control information, wherein the first uplink subframe is considered as the flexible uplink subframe when both of following conditions are satisfied: - the first uplink subframe is indicated as an uplink subframe by a first uplink-downlink subframe configuration for enhanced interface mitigation and traffic adaptation, eIMTA, fallback, the first uplink-downlink subframe configuration for eIMTA fallback being contained in system information block type 1, and - the first uplink subframe is indicated as a downlink subframe by a hybrid automatic repeat request, HARQ, reference configuration for the eIMTA fallback. performing blind decoding of scheduling information in a first uplink subframe of a first cell with a time division duplex, TDD, frame structure among the plurality of cells, by assuming the first uplink subframe as a downlink subframe when the first uplink subframe is a flexible uplink subframe; receiving downlink data via a second cell on an unlicensed band among the plurality of cells when the scheduling information including a downlink grant for the second cell is detected by the blind decoding; and transmitting, via the second cell, uplink control information piggy backed from the first cell, wherein modulation and coding scheme, MCS, information that is different from MCS information of the first cell is applied to the piggy backed uplink control information, wherein the first uplink subframe is considered as the flexible uplink subframe when both of following conditions are satisfied: - the first uplink subframe is indicated as an uplink subframe by a first uplink-downlink subframe configuration for enhanced interface mitigation and traffic adaptation, eIMTA, fallback, the first uplink-downlink subframe configuration for eIMTA fallback being contained in system information block type 1, and - the first uplink subframe is indicated as a downlink subframe by a hybrid automatic repeat request, HARQ, reference configuration for the eIMTA fallback. - the first uplink subframe is indicated as an uplink subframe by a first uplink-downlink subframe configuration for enhanced interface mitigation and traffic adaptation, eIMTA, fallback, the first uplink-downlink subframe configuration for eIMTA fallback being contained in system information block type 1, and - the first uplink subframe is indicated as a downlink subframe by a hybrid automatic repeat request, HARQ, reference configuration for the eIMTA fallback.