Transmission apparatus and method, and reception apparatus and method

A reception apparatus comprising:

• a reception circuit configured to receive a modulated signal from a transmission apparatus;
• a demodulating circuit configured to demodulate the modulated signal to generate second coded data blocks;
• and
• a decoding circuit configured to low-density parity-check decode the second coded data blocks,
• wherein the modulated signal has been generated by the transmission apparatus performing an encoding process, the encoding process including:
• adding known information data bits to information data bits to generate first data blocks;
• performing low-density parity-check encoding on the first data blocks to generate first coded data blocks including parity data blocks such that the first coded data blocks satisfy a first code rate;
• removing the known information data bits from the first coded data blocks to generate the second coded data blocks, the second coded data blocks satisfying a second code rate different from the first code rate;
• and
• modulating the second coded data blocks using a modulation scheme to generate the modulated signal, wherein
• a number of the known information data bits depends on a number of the information data bits such that the first code rate is fixed regardless of the number of the information data bits.