In order to transmit a codeword that is generated based on a quasi-cyclic low-density parity-check coding scheme and consists of N cyclic blocks each consisting of Q bits, a bit permutation is applied to the bits of the codeword, a plurality of constellation blocks each consisting of G×M bits are generated, and a block permutation is applied to the constellation blocks. The bit permutation is adopted for each of N/M sections each consisting M cyclic blocks such that the constellation blocks each consist of G×M bits from M distinct cyclic blocks of the associated section. The block permutation is equivalent to writing the constellation blocks into a matrix with R rows and (Q/(k×G)) columns and reading out the constellation blocks column by column from the matrix, where R is k×(N/M), and k is a positive integer.