LDPC code inspection matrix generation method and inspection matrix generation device

A method of generating check matrixes for irregular-LDPC codes using Euclid geometric codes, comprising:

• determining a maximum value of a column weight;
• determining Euclid geometric codes based on the maximum value of a column weight;
• determining a coding rate;
• searching an optimum ensemble of a row weight and a column weight according to a linear programming method in a state of a fixed coding rate, and so as to maximize a Gaussian noise;
• calculating an information length based on a predetermined block length and the coding rate;
• deleting a predetermined row based on the information length using the Euclid geometric codes;
• and
• dividing at random a row or a column of the matrixes after the row deletion in a predetermined order.

An apparatus that generates check matrixes for irregular-low-density parity-check codes, comprising:

• a weight determination unit that determines a maximum value of a column weight;
• a basic matrix determination unit that determines a basic matrix that fulfills conditions that the weights of a row and a column are constant and that the number of cycle is equal to or more than six based on the maximum value of a column weight;
• a coding rate determination unit that determines a coding rate;
• a weight searching unit that searches an optimum ensemble of a row weight and a column weight according to a linear programming method in a state of a fixed coding rate, and so as to maximize a Gaussian noise;
• an information calculation unit that calculates an information length based on a predetermined block length and the coding rate;
• a row deletion unit that deletes a predetermined row based on the information length using the basic matrix;
• and
• a division unit that divides at random a row or a column of the matrixes after the row deletion in a predetermined order.

An apparatus that generates check matrixes for irregular-LDPC codes using Euclid geometric codes, comprising:

• a weight determination unit that determines a maximum value of a column weight;
• a Euclid geometric code determination unit that determines Euclid geometric codes based on the maximum value of a column weight;
• a coding rate determination unit that determines a coding rate;
• a weight searching unit that searches an optimum ensemble of a row weight and a column weight according to a linear programming method in a state of a fixed coding rate, and so as to maximize a Gaussian noise;
• an information calculation unit that calculates an information length based on a predetermined block length and the coding rate;
• a row deletion unit that deletes a predetermined row based on the information length using the Euclid geometric codes;
• and
• a division unit that divides at random a row or a column of the matrixes after the row deletion in a predetermined order.

A communication apparatus that uses check matrixes for irregular-low-density parity-check codes, said check matrixes being generated by a method comprising:

• determining a maximum value of a column weight;
• determining a basic matrix that fulfills conditions that the weights of a row and a column are constant and that the number of cycles is equal to or more than six based on the maximum value of a column weight;
• determining a coding rate;
• searching an optimum ensemble of a row weight and a column weight according to a linear programming method in a state of a fixed coding rate, and so as to maximize a Gaussian noise;
• calculating an information length based on a predetermined block length and the coding rate;
• deleting a predetermined row based on the information length using the basic matrix;
• and carrying out a random division of a row column of the matrixes after the row deletion in a predetermined order.