Transmitter and method for generating additional parity thereof

A transmitting apparatus comprising:

• a zero padder configured to fill information bits with input bits and one or more zero padding bits, if a number of the input bits is less than a number of the information bits;
• an encoder configured to encode the information bits to generate parity bits based on a low density parity check (LDPC) code, a code rate of the LDPC code being 6/15 and a code length of the LDPC code being 16200 bits;
• a parity permutator configured to interleave the parity bits, split a codeword into a plurality of bit groups, the codeword comprising the information bits and the interleaved parity bits, and interleave bit groups including the interleaved parity bits among the plurality of bit groups based on a permutation order to provide an interleaved codeword;
• a puncturer configured to calculate a number of the parity bits to be punctured, and puncture one or more parity bits of the interleaved codeword based on the calculated number;
• a mapper configured to map the input bits and remaining parity bits of the interleaved codeword after the puncturing to constellation points, wherein the constellation points are based on quadrature phase shift keying (QPSK);
• and
• a transmitter configured to transmit a signal which is generated based on the constellation points,
• wherein bits of bit groups having indices of 35, 39, 20, 18, 43, 31, 36, 38, 22, 33, 28 and 41 among the plurality of bit groups are punctured, and
• wherein bit groups to be punctured are determined based on the permutation order and the calculated number.