An encoding method, comprising: determining a base matrix of size 42 rows × 52 columns denoted as base graph BG of a quasi-cyclic Low Density Parity Check Code, LDPC, code, where each element in the base graph BG is either "0" or "1", each "0" element in the base graph BG corresponds to an all-zero sub-matrix of size Z×Z in a parity check matrix of the quasi-cyclic LDPC code, each "1" element in the base graph BG corresponds to a circular permutation matrix, CPM, of size Z×Z in the parity check matrix of the quasi-cyclic LDPC code, and the CPM corresponding to an "1" element located at position (x, y) in the base graph BG is obtained by circularly shifting a unit matrix of size Z×Z to the right by P x,y times, wherein P x,y = mod ( V x,y,Z), and V x,y is a cyclic shift coefficient corresponding to the (x, y) th element in a cyclic coefficient exponent matrix of size 42 × 52 and each "0" element in the base graph BG is represented by "-1" at the corresponding position within the cyclic coefficient exponent matrix; dividing a set of dimensions Z of CPMs to be supported into a plurality of subsets according to a, wherein Z=a×2 j, including subset Set={3,6,12,24,48,96,192,384} for a=3 and 0≤j≤7; constructing a cyclic coefficient exponent matrix for the subset Set; obtaining the parity check matrix of the quasi-cyclic LDPC code by extending each cyclic coefficient as the corresponding CPM according to the constructed cyclic coefficient exponent matrix for the subset Set and the base graph BG; and performing quasi-cyclic LDPC encoding according to the obtained parity check matrix; wherein the constructed cyclic coefficient exponent matrix is shown by: determining a base matrix of size 42 rows × 52 columns denoted as base graph BG of a quasi-cyclic Low Density Parity Check Code, LDPC, code, where each element in the base graph BG is either "0" or "1", each "0" element in the base graph BG corresponds to an all-zero sub-matrix of size Z×Z in a parity check matrix of the quasi-cyclic LDPC code, each "1" element in the base graph BG corresponds to a circular permutation matrix, CPM, of size Z×Z in the parity check matrix of the quasi-cyclic LDPC code, and the CPM corresponding to an "1" element located at position (x, y) in the base graph BG is obtained by circularly shifting a unit matrix of size Z×Z to the right by P x,y times, wherein P x,y = mod ( V x,y,Z), and V x,y is a cyclic shift coefficient corresponding to the (x, y) th element in a cyclic coefficient exponent matrix of size 42 × 52 and each "0" element in the base graph BG is represented by "-1" at the corresponding position within the cyclic coefficient exponent matrix; each element in the base graph BG is either "0" or "1", each "0" element in the base graph BG corresponds to an all-zero sub-matrix of size Z×Z in a parity check matrix of the quasi-cyclic LDPC code, each "1" element in the base graph BG corresponds to a circular permutation matrix, CPM, of size Z×Z in the parity check matrix of the quasi-cyclic LDPC code, and the CPM corresponding to an "1" element located at position (x, y) in the base graph BG is obtained by circularly shifting a unit matrix of size Z×Z to the right by P x,y times, wherein P x,y = mod ( V x,y,Z), and V x,y is a cyclic shift coefficient corresponding to the (x, y) th element in a cyclic coefficient exponent matrix of size 42 × 52 and each "0" element in the base graph BG is represented by "-1" at the corresponding position within the cyclic coefficient exponent matrix; dividing a set of dimensions Z of CPMs to be supported into a plurality of subsets according to a, wherein Z=a×2 j, including subset Set={3,6,12,24,48,96,192,384} for a=3 and 0≤j≤7; constructing a cyclic coefficient exponent matrix for the subset Set; obtaining the parity check matrix of the quasi-cyclic LDPC code by extending each cyclic coefficient as the corresponding CPM according to the constructed cyclic coefficient exponent matrix for the subset Set and the base graph BG; and performing quasi-cyclic LDPC encoding according to the obtained parity check matrix; wherein the constructed cyclic coefficient exponent matrix is shown by: