Method of constructing low density parity check code, method of decoding the same and transmission system for the same

A method of decoding a Parity Check code, comprising:

• calculating a metric value corresponding to each codeword bit according to the constellation mapping scheme;
• blocking the metric values;
• regenerating, in real-time, a low density Parity Check matrix of a low density Parity Check code which is also used by a transmitter, the low density Parity Check matrix may be a Parity Check matrix generated by using a fixed pattern, the low density Parity Check matrix including a fixed pattern sub matrix constructed by selecting a proper fixed pattern from a fixed pattern set;
• performing a decoding operation of the low density Parity Check code in an iterated manner by using the blocked metric values and the regenerated Parity Check matrix to obtain hard-decision data corresponding to data from an information source of the transmitter;
• and
• outputting the hard-decision data.

A transmission system using a low density Parity Check code, the transmission system comprising a transmitting apparatus and a receiving apparatus, wherein the transmitting apparatus includes:

• means for firstly inputting data sent from an information source into a low density Parity Check matrix encoder for encoding, the encoder may be an encoder using a low density Parity Check matrix constructed by using a fixed pattern, the low density Parity Check matrix including a fixed pattern sub matrix constructed by selecting a proper fixed pattern from a fixed pattern set;
• means for delivering the data into a randomizer for randomizing;
• means for delivering the data into an interleaver for interleaving;
• and
• means for delivering the data through a modulator to transmit the data in air.

A transmission system using a low density Parity Check code, the transmission system comprising a transmitting apparatus and a receiving apparatus, wherein the receiving apparatus includes:

• means for receiving a radio-frequency signal in the air, performing down-conversion and filtering, and obtaining a baseband signal;
• means for delivering the baseband signal into a synchronizer to obtain a start position of the synchronization;
• means for intercepting data based on the start position of the synchronization, and performing operations including channel estimation and demodulation which are finished in a demodulator;
• means for delivering the outputted data into a de-interleaver to perform a de-interleaving operation;
• means for delivering the outputted data into a de-randomizer to perform a de-randomizing operation;
• means for delivering the outputted data into a low density Parity Check matrix decoder for decoding, the low density Parity Check matrix including a fixed pattern sub matrix constructed by selecting a proper fixed pattern from a fixed pattern set;
• and
• means for delivering the decoded data to an information sink.