Transmission Apparatus, Transmission Method, Reception Apparatus, and Reception Method

A transmission apparatus comprising:

• a coder that generates a codeword sequence s that is made up of zxnb bits and satisfies Equation 1 for information bit sequence u, using a parity check matrix H, z being an integer equal to or greater than 1, nb being an integer equal to or greater than 1, the codeword sequence s being a sequence having a parity bit sequence concatenated at a latter part of the information bit sequence u, the information bit sequence u being made up of zx(nb-mb) bits, the parity bit sequence being made up of zxmb bits, the codeword sequence s being decoded at a decoder of a communicating party, where
• Hs=0 (Equation 1)
• where the parity check matrix H is a parity check matrix of a low density parity check (LDPC) code of zxmb rows and zxnb columns configured by arranging submatrixes of z rows and z columns in mb rows and nb columns, and the codeword sequence s is a codeword sequence made up of zxnb rows and 1 column;
• a puncturer that forms a punctured codeword sequence obtained by removing bits from the codeword sequence s, using a puncturing pattern indicating whether or not bits are removed for each consecutive y bits from a first bit to a zxnb-th bit of the codeword sequence s, y being a divisor of z;
• a modulator that modulates the punctured codeword sequence using a predetermined modulation scheme to generate a modulated symbol sequence;
• and
• a transmitter that transmits the modulated symbol sequence.

A transmission method comprising:

• generating, by a processor, a codeword sequence a that is made up of zxnb bits and satisfies Equation 3 for information bit sequence u, using a parity check matrix H, z being an integer equal to or greater than 1, nb being an integer equal to or greater than 1, the codeword sequence s being a sequence having a parity bit sequence concatenated at a latter part of the information bit sequence u, the information bit sequence u being made up of zx(nb-mb) bits, the parity bit sequence being made up of zxmb bits, where
• Hs=0 (Equation 3)
• where the parity check matrix H is a parity check matrix of a low density parity check (LDPC) code of zxmb rows and zxnb columns configured by arranging submatrixes of z rows and z columns in mb rows and nb columns, and the codeword sequence s is a codeword sequence made up of zxnb rows and 1 column;
• forming a punctured codeword sequence obtained by removing bits from the codeword sequence s, using a puncturing pattern indicating whether or not bits are removed for each consecutive y bits from a first bit to a zxnb-th bit of the codeword sequence s, y being a divisor of z;
• modulating the punctured codeword sequence using a predetermined modulation scheme to generate a modulated symbol sequence;
• and
• transmitting the modulated symbol sequence.

A reception apparatus comprising:

• a receiver that receives a signal including a modulated symbol sequence;
• a demodulator that demodulates the modulated symbol sequence included in the received signal using a predetermined modulation scheme to generate a punctured codeword sequence;
• and
• a decoder that decodes the punctured codeword sequence to output information bit sequence u,
• wherein the modulated symbol sequence is generated by a process comprising:
• generating, by a processor, a codeword sequence s that is made up of zxnb bits and satisfies Equation 5 for the information bit sequence u, using the parity check matrix H, a being an integer equal to or greater than 1, nb being an integer equal to or greater than 1, the codeword sequence s being a sequence having a parity bit sequence concatenated at a latter pan of the information bit sequence u, the information bit sequence u being made up of zx(nb-mb) bits, the parity bit sequence being made up of zxmb bits, where
• Hs=0 (Equation 5)
• where the parity check matrix H is a parity check matrix of a low density parity check (LDPC) code of zxmb rows and zxnb columns configured by arranging submatrixes of z rows and z columns in mb rows and nb columns, and the codeword sequence s is a codeword sequence made up of zxnb rows and 1 column;
• forming the punctured codeword sequence obtained by removing bits from the codeword sequence s, using the puncturing pattern indicating whether or not bits are removed for each consecutive y bits from a first bit to a zxnb-th bit of the codeword sequence s, y being a divisor of z;
• modulating the punctured codeword sequence using the predetermined modulation scheme to generate the modulated symbol sequence;
• and
• transmitting the modulated symbol sequence.

A reception method comprising:

• receiving a signal including a modulated symbol sequence;
• demodulating the modulated symbol sequence included in the received signal using a predetermined modulation scheme to generate a punctured codeword sequence;
• and
• decoding the punctured codeword sequence to output information bit sequence u,
• wherein the modulated symbol sequence is generated by a process comprising:
• generating, by a processor, a codeword sequence s that is made up of zxnb bits and satisfies Equation 6 for the information bit sequence u, using the parity check matrix H, a being an integer equal to or greater than 1, nb being an integer equal to or greater than 1, the codeword sequence s being a sequence having a parity bit sequence concatenated at a latter part of the information bit sequence u, the information bit sequence u being made up of zx(nb-mb) bits, the parity bit sequence being made up of zxmb bits, where
• Hs=0 (Equation 6)
• where the parity check matrix H is a parity check matrix of a low density parity check (LDPC) code of zxmb rows and zxnb columns configured by arranging submatrixes of z rows and z columns in mb rows and nb columns, and the codeword sequence s is a codeword sequence made up of zxnb rows and 1 column;
• forming the punctured codeword sequence obtained by removing bits from the codeword sequence s, using the puncturing pattern indicating whether or not bits are removed for each consecutive y bits from a first bit to a zxnb-th bit of the codeword sequence s, y being a divisor of z;
• modulating the punctured codeword sequence using the predetermined modulation scheme to generate the modulated symbol sequence;
• and
• transmitting the modulated symbol sequence.