A method of transmitting a reception acknowledgement in a wireless communication system, the method performed by a user equipment comprising: determining M downlink subframes associated with an uplink subframe n at a specific uplink-downlink configuration, where M is greater than or equal to one and is the number of elements in a set K in accordance with the specific uplink-downlink configuration; counting a number of physical downlink control channels (PDCCHs) detected by the user equipment, each PDCCH in a subframe having a respective physical downlink shared channel (PDSCH) transmission in that subframe, to determine a counter value indicating a number of detected PDCCHs within downlink subframe n-k, where k represents an index of downlink subframes in the set K prior to the uplink subframe n, each PDCCH carrying a downlink assignment used for transmitting its respective PDSCH, receiving the downlink assignment including a bundling indicator indicating an accumulative number of PDCCHs up to a present subframe corresponding to the downlink assignment; determining a last bundling indicator having a value of a bundling indicator in a PDCCH detected by the user equipment in a downlink subframe n-ks, where ks is the smallest value in the set K; comparing the last bundling indicator and the counter value to determine whether at least one downlink assignment is missed; and transmitting an ACK/NACK signal on an uplink physical control channel (PUCCH) in the uplink subframe n, wherein the ACK/NACK signal is determined to be an ACK if all PDSCH transmissions over the M downlink subframes are correctly detected or a NACK if any one of the PDSCH transmissions over the M downlink subframes is detected in error; and wherein a resource used for transmission of the PUCCH is associated with a resource used for transmission of a PDCCH carrying the downlink assignment in the downlink subframe n-ks. determining M downlink subframes associated with an uplink subframe n at a specific uplink-downlink configuration, where M is greater than or equal to one and is the number of elements in a set K in accordance with the specific uplink-downlink configuration; counting a number of physical downlink control channels (PDCCHs) detected by the user equipment, each PDCCH in a subframe having a respective physical downlink shared channel (PDSCH) transmission in that subframe, to determine a counter value indicating a number of detected PDCCHs within downlink subframe n-k, where k represents an index of downlink subframes in the set K prior to the uplink subframe n, each PDCCH carrying a downlink assignment used for transmitting its respective PDSCH, receiving the downlink assignment including a bundling indicator indicating an accumulative number of PDCCHs up to a present subframe corresponding to the downlink assignment; determining a last bundling indicator having a value of a bundling indicator in a PDCCH detected by the user equipment in a downlink subframe n-ks, where ks is the smallest value in the set K; comparing the last bundling indicator and the counter value to determine whether at least one downlink assignment is missed; and transmitting an ACK/NACK signal on an uplink physical control channel (PUCCH) in the uplink subframe n, wherein the ACK/NACK signal is determined to be an ACK if all PDSCH transmissions over the M downlink subframes are correctly detected or a NACK if any one of the PDSCH transmissions over the M downlink subframes is detected in error; and wherein a resource used for transmission of the PUCCH is associated with a resource used for transmission of a PDCCH carrying the downlink assignment in the downlink subframe n-ks.