Coding and decoding

摘要

Error correction coding and decoding according to a serial concatenated modulation system are carried out under high code rate. A coding apparatus (1) comprises three convolutional coders (10, 30 and 50) for carrying out convolutional operation; two interleavers (20 and 40) for rearranging order of data input; and a multi-value mapping circuit (60) for carrying out mapping of a single point on the basis of a predetermined modulation system. The coding apparatus (1) carries out convolutional operation whose code rate is "2/3" as coding of extrinsic codes by a convolutional coder (10), and carries out convolutional operation whose code rate is "1" as coding of inner codes by a convolutional coder (50), and a multi-value modulation mapping circuit (60) applies mapping to a transmission symbol of a 8 PSK modulation system to output it as a single code transmission symbol. <IMAGE>