A method for transmitting ACK/NACK information in response to a downlink transmission in a relay node, RN, of a wireless communication system, the method comprising: receiving, by the RN from a base station, BS, one or more relay physical downlink control channels, R-PDCCHs, transmitted for scheduling one or more downlink transmissions; and receiving (S1220), by the RN from the BS, the one or more downlink transmissions according to the one or more R-PDCCHs in a downlink subframe set including M downlink subframes, where M is a positive integer; transmitting (S1230), by the RN to the BS, one or more ACK/NACK information for the one or more downlink transmissions in the downlink subframe set in one uplink subframe associated with the downlink subframe set, wherein the one uplink subframe includes N physical uplink control channel, PUCCH, resources, wherein the downlink subframe set and the uplink subframe are configured for a time division duplex, TDD, wherein the one or more R-PDCCHs are control channels different from a physical downlink control channel, PDCCH, wherein the N PUCCH resources respectively having indexes 0, 1, 2, ..., N-1 are configured by a higher layer, where M≤N, and N is a positive integer, wherein each of M PUCCH resources having the indexes 0, 1, 2, ..., M-1 among the configured N PUCCH resources respectively corresponds to a subframe in the M downlink subframes, and wherein based on the M downlink subframes being expressed by n-k t and the M PUCCH resources being expressed as n PUCCH,t , where t=0, 1, 2, ..., M-1 and k t corresponds to the index t such that a smallest kt value corresponds to the index t=0 and a next smallest kb value corresponds to the index t=1: the PUCCH resource n PUCCH,t corresponds to the downlink subframe n- k t , and a downlink subframe that is closest in time to an uplink subframe n is mapped to the PUCCH resource configured for the index t=0. receiving, by the RN from a base station, BS, one or more relay physical downlink control channels, R-PDCCHs, transmitted for scheduling one or more downlink transmissions; and receiving (S1220), by the RN from the BS, the one or more downlink transmissions according to the one or more R-PDCCHs in a downlink subframe set including M downlink subframes, where M is a positive integer; transmitting (S1230), by the RN to the BS, one or more ACK/NACK information for the one or more downlink transmissions in the downlink subframe set in one uplink subframe associated with the downlink subframe set, wherein the one uplink subframe includes N physical uplink control channel, PUCCH, resources, wherein the downlink subframe set and the uplink subframe are configured for a time division duplex, TDD, wherein the one or more R-PDCCHs are control channels different from a physical downlink control channel, PDCCH, wherein the N PUCCH resources respectively having indexes 0, 1, 2, ..., N-1 are configured by a higher layer, where M≤N, and N is a positive integer, wherein each of M PUCCH resources having the indexes 0, 1, 2, ..., M-1 among the configured N PUCCH resources respectively corresponds to a subframe in the M downlink subframes, and wherein based on the M downlink subframes being expressed by n-k t and the M PUCCH resources being expressed as n PUCCH,t , where t=0, 1, 2, ..., M-1 and k t corresponds to the index t such that a smallest kt value corresponds to the index t=0 and a next smallest kb value corresponds to the index t=1: the PUCCH resource n PUCCH,t corresponds to the downlink subframe n- k t , and a downlink subframe that is closest in time to an uplink subframe n is mapped to the PUCCH resource configured for the index t=0. the PUCCH resource n PUCCH,t corresponds to the downlink subframe n- k t , and a downlink subframe that is closest in time to an uplink subframe n is mapped to the PUCCH resource configured for the index t=0. <EOS>