A method for transmission of feedback information, comprising: transmitting, by a base station, data to a user equipment, UE, on three carriers simultaneously; receiving, by the base station, encoded feedback information of the three carriers from the UE in response to reception of the data; wherein the encoded feedback information of the three carriers is encoded Hybrid Automatic Repeat Request-Acknowledgement, HARQ-ACK, signals of the three carriers; characterized in that the encoded HARQ-ACK signals of the three carriers is a codeword into which HARQ-ACK signals of the three carriers are mapped according to the following mapping relationship between the HARQ-ACK signals of the three carriers and the codeword: ACK-DTX-DTX 1 1 1 1 1 1 1 1 1 1 NACK-DTX-DTX 0 0 0 0 0 0 0 0 0 0 DTX-ACK-DTX 1 1 1 1 1 0 0 0 0 0 DTX-NACK-DTX 0 0 0 0 0 1 1 1 1 1 DTX-DTX-ACK 1 1 0 0 0 1 1 0 0 0 DTX-DTX-NACK 0 0 1 1 1 0 0 1 1 1 ACK-ACK-DTX 1 0 1 0 1 0 1 0 1 0 ACK-NACK-DTX 1 1 0 0 1 1 0 0 1 1 NACK-ACK-DTX 0 0 1 1 0 0 1 1 0 0 NACK-NACK-DTX 0 1 0 1 0 1 0 1 0 1 ACK-DTX-ACK 1 0 1 1 0 1 1 0 0 1 ACK-DTX-NACK 0 1 0 1 1 0 1 0 0 1 NACK-DTX-ACK 0 0 0 1 1 1 1 0 1 0 NACK-DTX-NACK 1 0 0 1 1 1 0 1 0 0 DTX-ACK-ACK 0 1 1 1 0 1 0 0 1 0 DTX-ACK-NACK 1 0 1 0 0 1 0 1 1 0 DTX-NACK-ACK 0 1 1 0 0 0 1 0 1 1 DTX-NACK-NACK 0 0 0 0 1 0 1 0 1 1 ACK-ACK-ACK 1 1 0 1 0 0 1 1 1 0 ACK-ACK-NACK 0 1 1 0 1 1 1 1 0 0 ACK-NACK-ACK 1 0 0 1 0 0 0 0 1 1 ACK-NACK-NACK 0 0 1 0 1 1 0 0 0 1 NACK-ACK-ACK 1 1 1 0 0 0 0 1 0 1 NACK-ACK-NACK 0 1 0 0 1 0 0 1 1 0 NACK-NACK-ACK 1 0 0 0 1 0 1 1 0 1 NACK-NACK-NACK 1 1 1 1 0 1 0 1 0 0 wherein DTX represents discontinuous transmission, ACK represents acknowledgement, NACK represents negative acknowledgement. transmitting, by a base station, data to a user equipment, UE, on three carriers simultaneously; receiving, by the base station, encoded feedback information of the three carriers from the UE in response to reception of the data; wherein the encoded feedback information of the three carriers is encoded Hybrid Automatic Repeat Request-Acknowledgement, HARQ-ACK, signals of the three carriers; characterized in that the encoded HARQ-ACK signals of the three carriers is a codeword into which HARQ-ACK signals of the three carriers are mapped according to the following mapping relationship between the HARQ-ACK signals of the three carriers and the codeword: ACK-DTX-DTX 1 1 1 1 1 1 1 1 1 1 NACK-DTX-DTX 0 0 0 0 0 0 0 0 0 0 DTX-ACK-DTX 1 1 1 1 1 0 0 0 0 0 DTX-NACK-DTX 0 0 0 0 0 1 1 1 1 1 DTX-DTX-ACK 1 1 0 0 0 1 1 0 0 0 DTX-DTX-NACK 0 0 1 1 1 0 0 1 1 1 ACK-ACK-DTX 1 0 1 0 1 0 1 0 1 0 ACK-NACK-DTX 1 1 0 0 1 1 0 0 1 1 NACK-ACK-DTX 0 0 1 1 0 0 1 1 0 0 NACK-NACK-DTX 0 1 0 1 0 1 0 1 0 1 ACK-DTX-ACK 1 0 1 1 0 1 1 0 0 1 ACK-DTX-NACK 0 1 0 1 1 0 1 0 0 1 NACK-DTX-ACK 0 0 0 1 1 1 1 0 1 0 NACK-DTX-NACK 1 0 0 1 1 1 0 1 0 0 DTX-ACK-ACK 0 1 1 1 0 1 0 0 1 0 DTX-ACK-NACK 1 0 1 0 0 1 0 1 1 0 DTX-NACK-ACK 0 1 1 0 0 0 1 0 1 1 DTX-NACK-NACK 0 0 0 0 1 0 1 0 1 1 ACK-ACK-ACK 1 1 0 1 0 0 1 1 1 0 ACK-ACK-NACK 0 1 1 0 1 1 1 1 0 0 ACK-NACK-ACK 1 0 0 1 0 0 0 0 1 1 ACK-NACK-NACK 0 0 1 0 1 1 0 0 0 1 NACK-ACK-ACK 1 1 1 0 0 0 0 1 0 1 NACK-ACK-NACK 0 1 0 0 1 0 0 1 1 0 NACK-NACK-ACK 1 0 0 0 1 0 1 1 0 1 NACK-NACK-NACK 1 1 1 1 0 1 0 1 0 0 wherein DTX represents discontinuous transmission, ACK represents acknowledgement, NACK represents negative acknowledgement.