A BICM, Bit-Interleaved Coding and Modulation, encoding method comprising: a first encoding step of encoding first information bits into a first codeword according to a BCH, Bose-Chaudhuri-Hocquenghem, code; a second encoding step of encoding second information bits, which are constituted by the first codeword obtained in the first encoding step, into a second codeword according to a low density parity check code with code rate 7/15 and a codeword length of 16200, the low density parity check code shown in Table 1-1: a bit-interleaving step of conducting parity interleaving according to Math. 1 and column-row interleaving on bits of the second codeword obtained in the second encoding step, the column-row interleaving being conducted with or without twist, and u i = λ i: 0 ≤ i < K ldpc u K ldpc + 360 ⁢ t + s = λ K ldpc + Q ldpc s + t: 0 ≤ s < 360,0 ≤ t < Q ldpc where λ a denotes bits before parity interleaving, u b denotes bits after parity interleaving, K ldpc is 7560, Q ldpc is 24, and a and b are indices; a bit-to-cell demultiplexing step of demultiplexing a sequence of bits interleaved in the bit-interleaving step into 8 sub-bitstreams of bits v i,j' wherein i denotes one of the 8 sub-bitstreams and bit v i,j corresponds to bit v i+8xj of said sequence of interleaved bits, and performing a permutation on the 8 sub-bitstreams according to a predetermined permutation rule so as to permute each set of eight bits (v 0,q, v 1,q, v 2,q, v 3,q, v 4,q, v 5,q, v 6,q, v 7,q) of the 8 sub-bitstreams to a set of eight bits (b 0,q, b 1,q, b 2,q, b 3,q, b 4,q, b 5,q, b 6,q, b 7,q) to obtain 8 sub-bitstreams of permuted bits, where q is an index; and a mapping step of mapping each of 8-bit cell words (y 0,q, Y 1,q, y 2,q, y 3,q, y 4,q, y 5,q, Y 6,q, y 7.q) each composed of a set of eight bits (b 0,q, b 1,q, b 2,q, b 3,q, b 4,q, b 5,q, b 6,q, b 7,q) of the 8 sub-bitstreams of permuted bits obtained in the bit-to-cell demultiplexing step, into a complex cell (Re(Z q), Im(Z q)) according to the 256QAM, Quadrature Amplitude Modulation, constellation shown in Tables 1-2 and 1-3: [Table 1-2] y 0,q 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 y 2,q 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 y 4,q 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 y 6,q 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 Re( z q) -15 -13 -11 -9 -7 -5 -3 -1 1 3 5 7 9 11 13 15 [Table 1-3] y 1,q 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 y 3,q 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 y 5,q 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 y 7,q 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 lm( z q) -15 -13 -11 -9 -7 -5 -3 -1 1 3 5 7 9 11 13 15 wherein (b 0,q, b 1,q, b 2,q, b 3,q, b 4,q, b 5,q, b 6,q, b 7,q) = (y 0,q, y 1,q, y 2,q, y 3,q, y 4,q, y 5,q, y 6,q, y 7,q), and the predetermined permutation rule is: v 0,q = b 2,q, v 1,q = b 6,q, V 2,q = b 0,q, v 3,q = b 1,q, v 4,q = b 4,q, v 5,q = b 5,q, v 6,q = b 3,q, v 7,q = b 7,q. a first encoding step of encoding first information bits into a first codeword according to a BCH, Bose-Chaudhuri-Hocquenghem, code; a second encoding step of encoding second information bits, which are constituted by the first codeword obtained in the first encoding step, into a second codeword according to a low density parity check code with code rate 7/15 and a codeword length of 16200, the low density parity check code shown in Table 1-1: a bit-interleaving step of conducting parity interleaving according to Math. 1 and column-row interleaving on bits of the second codeword obtained in the second encoding step, the column-row interleaving being conducted with or without twist, and u i = λ i: 0 ≤ i < K ldpc u K ldpc + 360 ⁢ t + s = λ K ldpc + Q ldpc s + t: 0 ≤ s < 360,0 ≤ t < Q ldpc where λ a denotes bits before parity interleaving, u b denotes bits after parity interleaving, K ldpc is 7560, Q ldpc is 24, and a and b are indices; a bit-to-cell demultiplexing step of demultiplexing a sequence of bits interleaved in the bit-interleaving step into 8 sub-bitstreams of bits v i,j' wherein i denotes one of the 8 sub-bitstreams and bit v i,j corresponds to bit v i+8xj of said sequence of interleaved bits, and performing a permutation on the 8 sub-bitstreams according to a predetermined permutation rule so as to permute each set of eight bits (v 0,q, v 1,q, v 2,q, v 3,q, v 4,q, v 5,q, v 6,q, v 7,q) of the 8 sub-bitstreams to a set of eight bits (b 0,q, b 1,q, b 2,q, b 3,q, b 4,q, b 5,q, b 6,q, b 7,q) to obtain 8 sub-bitstreams of permuted bits, where q is an index; and a mapping step of mapping each of 8-bit cell words (y 0,q, Y 1,q, y 2,q, y 3,q, y 4,q, y 5,q, Y 6,q, y 7.q) each composed of a set of eight bits (b 0,q, b 1,q, b 2,q, b 3,q, b 4,q, b 5,q, b 6,q, b 7,q) of the 8 sub-bitstreams of permuted bits obtained in the bit-to-cell demultiplexing step, into a complex cell (Re(Z q), Im(Z q)) according to the 256QAM, Quadrature Amplitude Modulation, constellation shown in Tables 1-2 and 1-3: [Table 1-2] y 0,q 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 y 2,q 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 y 4,q 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 y 6,q 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 Re( z q) -15 -13 -11 -9 -7 -5 -3 -1 1 3 5 7 9 11 13 15 [Table 1-3] y 1,q 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 y 3,q 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 y 5,q 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 y 7,q 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 lm( z q) -15 -13 -11 -9 -7 -5 -3 -1 1 3 5 7 9 11 13 15 wherein (b 0,q, b 1,q, b 2,q, b 3,q, b 4,q, b 5,q, b 6,q, b 7,q) = (y 0,q, y 1,q, y 2,q, y 3,q, y 4,q, y 5,q, y 6,q, y 7,q), and the predetermined permutation rule is: v 0,q = b 2,q, v 1,q = b 6,q, V 2,q = b 0,q, v 3,q = b 1,q, v 4,q = b 4,q, v 5,q = b 5,q, v 6,q = b 3,q, v 7,q = b 7,q.