Patent ID: 6910170

Claim:
A pre-decoder for a turbo decoder for decoding a turbo code consisting of a data symbol stream and a plurality of parity symbol streams, parts of which are punctured, the pre-decoder comprising: an arithmetic unit for carrying out, with respect to a binary-converted data bit stream, the same algorithm that a turbo encoder performs for generating parity bit streams, and generating estimated parity bit streams; a comparison unit for comparing non-punctured bits of binary-converted parity bit streams with the estimated parity bit streams generated by the arithmetic unit; a modulation unit for modulating the estimated parity bit streams into estimated parity symbol streams; and a recovery unit for recovering punctured parts of the parity symbol streams by substituting symbols of the estimated parity symbol streams for corresponding punctured parts of the parity symbol streams, when related non-punctured bits of the binary-converted parity bit streams are identical with corresponding bits of the estimated parity bit streams, according to comparison result results of the comparison unit.