A terminal, comprising: a receiving module, configured to receive downlink scheduling information of a downlink subframe F(i, j), wherein the downlink subframe F(i, j) is a subframe in a set M of preconfigured downlink subframes corresponding to an uplink subframe; wherein F(i, j) represents a downlink subframe j on a carrier i configured for the terminal, i ∈ C, C is a set of all carriers configured for the terminal for downlink data transmission, j ∈ K, and K is a set of downlink subframes corresponding to the uplink subframe; the set M of preconfigured downlink subframes is divided into N subsets of preconfigured downlink subframes, N is an integer greater than or equal to 2, a bit quantity of a hybrid automatic repeat request-acknowledgement, HARQ-ACK, that needs to be fed back for each downlink subframe in one subset of preconfigured downlink subframes is a predetermined value, and bit quantities of HARQ-ACKs that need to be fed back for any downlink subframes in different subsets of preconfigured downlink subframes are different; and the receiving module is further configured to receive, in the downlink subframe F(i, j), downlink data scheduled by the downlink scheduling information; a processing module, configured to: generate a HARQ-ACK codebook according to a receiving status of the downlink data received by the receiving module in the downlink subframe F(i, j) and a bit quantity of a HARQ-ACK that needs to be fed back for the downlink subframe F(i, j), wherein the HARQ-ACK codebook comprises at least one sub-codebook, the at least one sub-codebook is in one-to-one correspondence with at least one subset of preconfigured downlink subframes, the at least one subset of preconfigured downlink subframes is at least one of the N subsets of preconfigured downlink subframes, and the at least one subset of preconfigured downlink subframes is a subset comprising the downlink subframe in which the terminal receives the downlink data scheduled by the downlink scheduling information; and generate uplink control information by encoding the HARQ-ACK codebook; and a sending module, configured to send the uplink control information in the uplink subframe. a receiving module, configured to receive downlink scheduling information of a downlink subframe F(i, j), wherein the downlink subframe F(i, j) is a subframe in a set M of preconfigured downlink subframes corresponding to an uplink subframe; wherein F(i, j) represents a downlink subframe j on a carrier i configured for the terminal, i ∈ C, C is a set of all carriers configured for the terminal for downlink data transmission, j ∈ K, and K is a set of downlink subframes corresponding to the uplink subframe; the set M of preconfigured downlink subframes is divided into N subsets of preconfigured downlink subframes, N is an integer greater than or equal to 2, a bit quantity of a hybrid automatic repeat request-acknowledgement, HARQ-ACK, that needs to be fed back for each downlink subframe in one subset of preconfigured downlink subframes is a predetermined value, and bit quantities of HARQ-ACKs that need to be fed back for any downlink subframes in different subsets of preconfigured downlink subframes are different; and the receiving module is further configured to receive, in the downlink subframe F(i, j), downlink data scheduled by the downlink scheduling information; a processing module, configured to: generate a HARQ-ACK codebook according to a receiving status of the downlink data received by the receiving module in the downlink subframe F(i, j) and a bit quantity of a HARQ-ACK that needs to be fed back for the downlink subframe F(i, j), wherein the HARQ-ACK codebook comprises at least one sub-codebook, the at least one sub-codebook is in one-to-one correspondence with at least one subset of preconfigured downlink subframes, the at least one subset of preconfigured downlink subframes is at least one of the N subsets of preconfigured downlink subframes, and the at least one subset of preconfigured downlink subframes is a subset comprising the downlink subframe in which the terminal receives the downlink data scheduled by the downlink scheduling information; and generate uplink control information by encoding the HARQ-ACK codebook; and a sending module, configured to send the uplink control information in the uplink subframe.