ИСТИНА

Provided is a IR-HARQ scheme comprising determining a first low-density-parity-check, LDPC, matrix, wherein a second submatrix of the first LDPC matrix has a dual diagonal structure, determining a codeword based on a sequence of information bits and the first LDPC matrix, transmitting the codeword, receiving, in relation to the transmitted codeword, an IR-HARQ message, determining a second LDPC matrix, wherein a first submatrix of the second LDPC matrix is determined by splitting rows of a first submatrix of the first LDPC matrix and a second submatrix of the second LDPC matrix has a dual diagonal structure, determining a desired column weight distribution of the second LDPC matrix, adding rows to the first submatrix and to the second submatrix of the second LDPC matrix, wherein a number of nonzero entries in the columns of the rows added to the first submatrix of the second LDPC matrix is based on the desired column weight distribution and wherein entries in the columns of the rows added to the second submatrix of the second LDPC matrix are zero, determining additional parity bits for the codeword based on the sequence of information bits and the second LDPC matrix, and transmitting the additional parity bits.