A disclosure of the present specification provides a method for transmitting data by a transmitter. The method may comprise the steps of: when a transport block (TB) is divided into n data blocks, adding additional information after each of the n data blocks; and adding a cyclic redundancy check (CRC) after the last additional information. Here, the CRC may be generated on the basis of the n data blocks, and the n pieces of additional information added after each of data blocks.