Provided are a method, base station, and user equipment for transmitting/receiving hybrid automatic repeat request (HARQ) messages. Specifically, the method for transmitting HARQ messages comprises the following steps: converting a time division duplex (TDD) uplink-downlink configuration scheme from a first scheme into a second scheme; determining that a HARQ message corresponding to data in an uplink subframe that is based on a first scheme is to be transmitted in a subframe that is based on a second scheme; and selecting, on the basis of predetermined HARQ timing, a subframe to be used for the transmission of the HARQ message such that the selected subframe conforms to the second scheme, wherein the predetermined HARQ timing corresponds to a predetermined TDD uplink-downlink configuration scheme and the set of downlink subframes designated in the predetermined TDD uplink-downlink configuration scheme is a subset of the set of downlink subframes designated in the first scheme and the set of downlink subframes designated in the second scheme.

A base station calculates the size of sub-bands on the basis of a system bandwidth and divides the sub-bands. The base station selects some of the sub-bands, forms the selected sub-bands into a sub-band set, assigns the sub-band set to a user equipment (UE), and reports information associated with the sub-band set to the user equipment (UE). The user equipment (UE) recalculates the size of the corresponding sub-bands and the number of sub-bands used for feedback on the basis of the size of the assigned sub-band set. Moreover, the user equipment (UE) divides the sub-band set into the corresponding sub-bands and feeds back information associated with a predetermined number of sub-bands to the base station according to the result of the calculation. The base station performs the optimization of a transmitter according to the information fed back by the user equipment (UE), thereby realizing an object to improve the efficiency of the system on the assumption that the service quality of a radio cell is ensured.