Low density parity check code encoding method and communication apparatus

A computer program product comprising programming instructions stored in a computer readable storage medium for enabling a computer to perform operations comprising:

• performing, based on a first check matrix, low-density parity-check (LDPC) code encoding on an information bit sequence to obtain a first codeword at a first code rate, wherein:
• the first check matrix is obtained by reading i rows and j columns from a mother matrix,
• the mother matrix comprises:
• a basic matrix, an extension matrix, a first fixed matrix, and a second fixed matrix,
• the basic matrix is located at a top-left corner of the mother matrix,
• the extension matrix is located at a bottom-left corner of the mother matrix,
• the first fixed matrix is located at a top-right corner of the mother matrix,
• the second fixed matrix is located at a bottom-right corner of the mother matrix,
• a quantity of rows in the basic matrix is equal to a quantity of rows in the first fixed matrix,
• a quantity of rows in the extension matrix is equal to a quantity of rows in the second fixed matrix,
• a quantity of columns in the extension matrix is equal to a quantity of columns in the basic matrix,
• a quantity of columns in the first fixed matrix is equal to a quantity of columns in the second fixed matrix,
• i=p+k, j=q+k, p and q are respectively the quantity of rows and the quantity of columns in the basic matrix,
• k≥0, and
• i, j, p, q, and k are all integers;
• and
• sending the first codeword.