A method for transmitting, Hybrid Automatic Repeat Request-Acknowledgement, HARQ-ACK, information in a communication system in which three carriers are configured and at least one of the three carriers uses MIMO mode, the method comprises: encoding, by a user equipment, HARQ-ACK information of the three carriers; and transmitting, by the user equipment, the encoded HARQ-ACK information of the three carriers to a base station; characterized in that the encoded HARQ-ACK information of the three carriers comprises a first codeword and a second codeword; the first codeword represents encoded HARQ-ACK information of a first carrier and a second carrier according to an encoding scheme of dual-carrier configured with Multiple-Input Multiple-Output, DC-MIMO, and the second codeword represents encoded HARQ-ACK information of a third carrier according to the encoding scheme of DC-MIMO in Dual stream-DTX or DTX-dual stream mode or in Single stream-DTX or DTX-single stream mode; and the encoding scheme of DC-MIMO is as follows: HARQ-ACK information codeword D/A 0 0 0 0 0 0 1 1 1 1 D/N 1 1 1 1 1 1 0 0 0 0 D/AA 1 0 0 0 1 0 0 0 1 1 D/AN 0 1 0 0 0 0 1 1 0 1 D/NA 0 0 0 1 1 1 1 1 1 0 D/NN 1 1 1 1 1 0 0 1 0 0 A/D 1 1 1 1 1 1 1 1 1 1 A/A 1 1 0 1 0 0 0 0 1 1 A/N 0 0 1 1 1 0 1 0 0 1 A/AA 1 0 1 0 0 1 1 0 0 0 A/AN 1 0 0 1 0 1 0 1 0 1 A/NA 0 0 1 1 1 0 1 0 0 1 A/NN 0 1 1 1 0 1 0 0 1 1 N/D 0 0 0 0 0 0 0 0 0 0 N/A 1 0 0 1 0 1 1 1 0 0 N/N 0 1 1 0 0 1 0 1 0 1 N/AA 1 1 0 1 0 0 1 0 1 0 N/AN 1 1 0 0 0 1 0 1 1 0 N/NA 0 1 1 0 1 0 1 0 1 0 N/NN 0 0 1 0 1 1 0 1 0 1 AA/D 1 0 1 0 1 1 1 1 0 1 AA/A 0 1 1 0 0 0 0 1 0 0 AA/N 1 1 1 0 0 1 1 0 1 0 AA/AA 0 1 1 0 1 1 0 1 1 1 AA/AN 1 0 1 1 0 0 1 1 1 1 AA/NA 1 1 0 1 1 1 1 0 0 1 AA/NN 0 1 1 1 0 1 1 1 0 0 AN/D 1 1 0 1 0 1 0 1 1 1 AN/A 1 0 1 1 1 0 0 1 1 0 AN/N 0 0 1 1 0 1 0 0 0 1 AN/AA 0 0 0 1 1 0 0 1 0 1 AN/AN 1 1 1 0 0 0 0 0 0 1 AN/NA 1 0 0 0 0 1 0 1 0 0 AN/NN 0 0 1 1 0 1 0 0 0 1 NA/D 0 1 1 1 1 0 1 0 1 1 NA/A 0 1 0 1 1 1 1 1 0 0 NA/N 1 1 0 0 1 0 0 0 0 1 NA/AA 1 1 0 0 1 0 1 1 1 0 NA/AN 0 0 1 0 1 0 1 0 0 0 NA/NA 1 0 1 1 1 1 0 0 1 0 NA/NN 1 1 1 0 0 1 1 0 1 0 NN/D 1 0 0 1 0 0 1 0 0 0 NN/A 0 0 0 0 1 1 0 0 1 0 NN/N 0 1 0 0 0 1 1 0 0 1 NN/AA 0 1 0 1 0 0 0 0 1 0 NN/AN 0 0 1 0 0 0 0 1 1 0 NN/NA 0 1 0 0 1 1 0 0 0 0 NN/NN 0 0 0 0 0 1 1 0 1 1 wherein D represents discontinuous transmission, DTX, A represents Acknowledgement, ACK, N represents Negative Acknowledgement, NACK, AA represents ACK_ACK, AN represents ACK_NACK, NA represents NACK_ACK, and NN represents NACK_NACK. encoding, by a user equipment, HARQ-ACK information of the three carriers; and transmitting, by the user equipment, the encoded HARQ-ACK information of the three carriers to a base station; characterized in that the encoded HARQ-ACK information of the three carriers comprises a first codeword and a second codeword; the first codeword represents encoded HARQ-ACK information of a first carrier and a second carrier according to an encoding scheme of dual-carrier configured with Multiple-Input Multiple-Output, DC-MIMO, and the second codeword represents encoded HARQ-ACK information of a third carrier according to the encoding scheme of DC-MIMO in Dual stream-DTX or DTX-dual stream mode or in Single stream-DTX or DTX-single stream mode; and the encoding scheme of DC-MIMO is as follows: HARQ-ACK information codeword D/A 0 0 0 0 0 0 1 1 1 1 D/N 1 1 1 1 1 1 0 0 0 0 D/AA 1 0 0 0 1 0 0 0 1 1 D/AN 0 1 0 0 0 0 1 1 0 1 D/NA 0 0 0 1 1 1 1 1 1 0 D/NN 1 1 1 1 1 0 0 1 0 0 A/D 1 1 1 1 1 1 1 1 1 1 A/A 1 1 0 1 0 0 0 0 1 1 A/N 0 0 1 1 1 0 1 0 0 1 A/AA 1 0 1 0 0 1 1 0 0 0 A/AN 1 0 0 1 0 1 0 1 0 1 A/NA 0 0 1 1 1 0 1 0 0 1 A/NN 0 1 1 1 0 1 0 0 1 1 N/D 0 0 0 0 0 0 0 0 0 0 N/A 1 0 0 1 0 1 1 1 0 0 N/N 0 1 1 0 0 1 0 1 0 1 N/AA 1 1 0 1 0 0 1 0 1 0 N/AN 1 1 0 0 0 1 0 1 1 0 N/NA 0 1 1 0 1 0 1 0 1 0 N/NN 0 0 1 0 1 1 0 1 0 1 AA/D 1 0 1 0 1 1 1 1 0 1 AA/A 0 1 1 0 0 0 0 1 0 0 AA/N 1 1 1 0 0 1 1 0 1 0 AA/AA 0 1 1 0 1 1 0 1 1 1 AA/AN 1 0 1 1 0 0 1 1 1 1 AA/NA 1 1 0 1 1 1 1 0 0 1 AA/NN 0 1 1 1 0 1 1 1 0 0 AN/D 1 1 0 1 0 1 0 1 1 1 AN/A 1 0 1 1 1 0 0 1 1 0 AN/N 0 0 1 1 0 1 0 0 0 1 AN/AA 0 0 0 1 1 0 0 1 0 1 AN/AN 1 1 1 0 0 0 0 0 0 1 AN/NA 1 0 0 0 0 1 0 1 0 0 AN/NN 0 0 1 1 0 1 0 0 0 1 NA/D 0 1 1 1 1 0 1 0 1 1 NA/A 0 1 0 1 1 1 1 1 0 0 NA/N 1 1 0 0 1 0 0 0 0 1 NA/AA 1 1 0 0 1 0 1 1 1 0 NA/AN 0 0 1 0 1 0 1 0 0 0 NA/NA 1 0 1 1 1 1 0 0 1 0 NA/NN 1 1 1 0 0 1 1 0 1 0 NN/D 1 0 0 1 0 0 1 0 0 0 NN/A 0 0 0 0 1 1 0 0 1 0 NN/N 0 1 0 0 0 1 1 0 0 1 NN/AA 0 1 0 1 0 0 0 0 1 0 NN/AN 0 0 1 0 0 0 0 1 1 0 NN/NA 0 1 0 0 1 1 0 0 0 0 NN/NN 0 0 0 0 0 1 1 0 1 1 wherein D represents discontinuous transmission, DTX, A represents Acknowledgement, ACK, N represents Negative Acknowledgement, NACK, AA represents ACK_ACK, AN represents ACK_NACK, NA represents NACK_ACK, and NN represents NACK_NACK. D represents discontinuous transmission, DTX, A represents Acknowledgement, ACK, N represents Negative Acknowledgement, NACK, AA represents ACK_ACK, AN represents ACK_NACK, NA represents NACK_ACK, and NN represents NACK_NACK.