Serial concatenated ldpc encoder, decoder and decoding method thereof

A serial concatenated LDPC(Low Density Parity Check) encoder, a decoder and a decoding method using the same are provided to improve a performance without increasing the decoding complexity of a circuit although a global iterative decoding is performed. A serial concatenated LDPC encoder includes an external LDPC encoder(10), a block interleaver(20), an internal LDPC encoder(11), and a channel interleaver. The external LDPC encoder receives k-bit information column s={s1, s2, s3, ... sk}, and encodes n-bit column t={t1, t2, t3, ... tn}. The block interleaver interleaves the encoded n-bit column t={t1, t2, t3, ... tn}. The internal LDPC encoder encodes the interleaved I-bit column u={u1, u2, u3, ... ul}, and outputs the encoded l-bit column as a transmission code word. The channel interleaver is coupled to the internal LDPC encoder.