Apparatus and method for generating codes in a communications system

A method of rearranging matrixes of sub-codes of QCTCs, comprising the steps of:

• generating sub-code sets of QCTCs corresponding to a plurality of given code rates, each sub-code of the sub-code set being a matrix with elements representing repetition and puncturing;
• generating new sub-code sets, a matrix of each sub-code in a new sub-code set having as many columns as a least common multiple of the numbers of columns of sub-codes in the sub-code sets;
• determining priority of the matrixes of sub-codes in each new sub-code set so that a matrix generated by combining matrixes from two of the new sub-code sets has a QCTC characteristic;
• and
• rearranging the matrixes in each new sub-code according to the priority.

A method of transmitting symbols using sub-codes of two-dimensional QCTCs, comprising the steps of:

• rearranging sub-codes in sub-code sets of QCTCs corresponding to a plurality of given code rates and storing the rearranged sub-codes;
• selecting a QCTC with a code rate determined for transmission;
• and
• transmitting symbols using a sub-code in the sub-code set of the selected QCTC.

A method of generating sub-codes of two-dimensional QCTCs, comprising the steps of:

• generating sub-codes of a QCTC with the highest code rate among QCTCs with code rates in an integer-multiple relation and setting the QCTC with the highest code rate as a primitive code;
• determining a number of sub-codes to be grouped in the primitive code to generate each of the other QCTCs;
• and
• generating sub-codes of the other QCTCs by grouping the sub-codes of the primitive code according to grouping numbers.

A method of transmitting symbols using sub-codes of two-dimensional QCTCs, comprising the steps of:

• generating sub-codes of a QCTC with the highest code rate among QCTCs with code rates in an integer-multiple relation and setting the QCTC with the highest code rate as a primitive code;
• determining a number of sub-codes to be grouped in the primitive code to generate each of the other QCTCs;
• and
• generating a sub-code by grouping as many sub-codes of the primitive code as a grouping number corresponding to a determined code rate for transmission, starting with a sub-code following a previously transmitted sub-code in the primitive code, and transmitting symbols using the generated sub-code.

A method of transmitting symbols using sub-codes of two-dimensional QCTCs, comprising the steps of:

• generating sub-codes of a QCTC with the highest code rate among QCTCs with code rates in an integer-multiple relation and setting the QCTC with the highest code rate as a primitive code;
• generating sub-codes of the other QCTCs by grouping the sub-codes of the primitive code;
• determining a sequence number, j current to be used in transmission by the following equation when a code rate for transmission is given
• [((j—pre+1)*g—pre mod Sp)−1]+1=(j—current*g—current)mod Sp
• where j_pre is a sequence number of sub-code used for the previous transmission, g_pre is a grouping number used for the previous transmission, g current is a determined grouping number and Sp is a set size of the primitive code;
• and
• transmitting symbols using a sub-code corresponding to the determined sequence number among sub-codes of the QCTC according to the determined code rate

A method of generating sub-codes of two-dimensional QCTCs, comprising the steps of:

• grouping QCTCs according to code rates, each QCTC group including QCTCs with code rates in an integer-multiple relation;
• generating sub-codes of a QCTC with the highest code rate in each QCTC group and setting the QCTC with the highest code rate as a primitive code;
• determining a number of sub-codes to be grouped in the primitive code to generate each of the other QCTCs in each QCTC group;
• and
• generating a sub-code by grouping as many sub-codes of the primitive code as a grouping number corresponding to a code rate.

A method of transmitting symbols using sub-codes of two-dimensional QCTCs, comprising the steps of:

• grouping QCTCs according to code rates, each QCTC group including QCTCs with code rates in an integer-multiple relation;
• generating sub-codes of a QCTC with the highest code rate in each QCTC group and setting the QCTC with the highest code rate as a primitive code;
• determining a number of sub-codes to be grouped in the primitive code to generate each of the other QCTCs in each QCTC group;
• and
• generating a sub-code by grouping as many sub-codes of the primitive code as a grouping number corresponding to a determined code rate for transmission and transmitting symbols using the generated sub-code.

An apparatus for rearranging sub-codes of two-dimensional QCTCs, comprising:

• a turbo encoder for encoding an input information bit stream with a predetermined code rate and generating code symbols;
• a controller for rearranging sub-codes in sub-code sets of QCTCs corresponding to a plurality of given code rates and storing the rearranged sub-codes, selecting a QCTC with a code rate determined for transmission, and generating a puncturing and repetition control signal for a matrix following a matrix used for a previous transmission among the rearranged matrixes of the selected QCTC;
• and
• a QCTC generator for generating a sub-code to be transmitted by puncturing and repeating the code symbols received from the turbo encoder according to the puncturing and repetition control signal.

An apparatus for transmitting symbols using sub-codes of two-dimensional QCTCs, comprising:

• a turbo encoder for encoding an input information bit stream with a predetermined code rate and generating code symbols;
• a controller for storing a set of matrixes from which to generate sub-codes of a QCTC with the highest code rate among QCTCs with code rates in an integer-multiple relation, setting the QCTC with the highest code rate as a primitive code, generating sub-codes of QCTCs by grouping the sub-codes of the primitive code, selecting a sub-code of QCTC according to the determined code rate when the code rate for the transmission is given, and generating a puncturing and repetition control signal according to the selected sub-code ;
• and
• a QCTC generator for generating a sub-code to be transmitted by puncturing and repeating the code symbols received from the turbo encoder according to the puncturing and repetition control signal.