Encoding/decoding apparatus using low density parity check code

A decoding apparatus for decoding LDPC code encoded codewords received from an encoding apparatus in a hybrid automatic repeat request system, the decoding apparatus comprising:

• a first LDPC code decoder and a second LDPC code decoder for performing LDPC code decoding on an LDPC code coded codeword transmitted from the encoding apparatus;
• an interleaver for interleaving an output of the first LDPC code decoder and outputting the interleaved data to the second LDPC code decoder;
• and
• a deinterleaver for deinterleaving an output of the second LDPC code decoder and outputting the deinterleaved data to the first LDPC code decoder,
• wherein the first LDPC code decoder performs decoding on the codeword newly received from the encoding apparatus and an odd numbered codeword retransmitted from the encoding apparatus due to a transmission error,
• the second LDPC code decoder performs decoding on an even numbered codeword retransmitted from the encoding apparatus due to a transmission error,
• the codeword newly transmitted from the encoding apparatus is processed and then finally outputted from the first LDPC code decoder, and
• the codeword retransmitted from the encoding apparatus is processed and then finally outputted from the deinterleaver.

An encoding apparatus for encoding input information data using LDPC (low density parity check) codes and transmitting encoded data to a decoding apparatus in a hybrid automatic repeat request system, the encoding apparatus comprising:

• a first LDPC code encoder for performing LDPC code encoding on the input information data and transmitting the encoded data to the decoding apparatus;
• an interleaver for interleaving the output of the first LDPC code encoder;
• and
• a second LDPC code encoder connected in series with the interleaver, for performing encoding on an output of the interleaver, and transmitting encoded data to the decoding apparatus;
• wherein the first LDPC code encoder performs an odd numbered retransmission on the input information data according to a retransmission request from the decoding apparatus;
• the second LDPC code encoder performs an even numbered retransmission on the input information data according to the retransmission request from the decoding apparatus;
• and
• the codeword transmitted by the encoding apparatus is finally output by the first LDPC code decoder.

A decoding apparatus for decoding codewords, encoded with LDPC codes, received from an encoding apparatus in a hybrid automatic repeat request system, the decoding apparatus comprising:

• a first LDPC code decoder and a second LDPC code decoder for performing LDPC code decoding on the codeword transmitted from the encoding apparatus;
• an interleaver for interleaving an output of the first LDPC code decoder and outputting a result to the second LDPC code decoder;
• and
• a deinterleaver for deinterleaving the output of the second LDPC code decoder and outputting a result to the first LDPC code decoder,
• wherein the first LDPC code decoder performs decoding on a codeword newly received from the encoding apparatus and an odd numbered codeword retransmitted from the encoding apparatus due to a transmission error, and
• the second LDPC code decoder performs decoding on an even numbered codeword retransmitted from the encoding apparatus due to the transmission error.