IP Library › Granted Patent US 7,516,388
Granted Patent B2
US 7,516,388 · App. 10/482,484 · Granted Apr 7, 2009

LDPC code inspection matrix generation method

Assignee: Mitsubishi Electric Corporation
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Quick Facts
Patent No.
US 7,516,388
App. No.
10/482,484
Granted
Apr 7, 2009
Kind
B2
Abstract

A method of generating check matrixes for LDPC codes includes analyzing a “Sum-Product Algorithm” for Low-Density Parity-Check codes, on the assumption that a Log Likelihood Ratio between input/output data at a decoder can be approximated in a Gaussian distribution; fixing a coding rate; obtaining an optimal ensemble, which is an ensemble that minimizes the threshold of SNR, of row and column weights in one linear programming to maximize a Gaussian noise; and generating a check matrix for LDPC codes in accordance with the ensemble obtained.

Claims (49)

1. A method of generating check matrixes for Low-Density Parity-Check codes to derive a threshold of Signal to Noise Ratio that provides an error with a value of 0 by analyzing a Sum Product Algorithm for the Low-Density Parity-Check codes, on an assumption that a Log Likelihood Ratio between input/output data at a decoder is approximated in a Gaussian distribution, comprising:

utilizing an encoder for fixing a coding rate;

utilizing the encoder for obtaining an optimal ensemble, which is an ensemble that minimizes the threshold of Signal to Noise Ratio, of a row and a column weights in a linear programming, wherein the linear programming is employed to search optimal generator functions to maximize a Gaussian noise; and

utilizing the encoder for generating a check matrix for the Low-Density Parity-Check codes in accordance with the ensemble obtained.

2. The method according to claim 1 , further comprising extracting “1” at random from each row or each column in Euclid geometric codes based on the ensemble obtained, and

the generating includes dividing each row or each column to generate a check matrix for Irregular Low-Density Parity-Check codes.

3. The method according to claim 2 , further comprising:

adjusting a weight distribution in the ensemble obtained such that the total weight number of weight units is equal to an integer, and a sum of the total weight numbers of weight units is equal to the total number of “1”s in Euclid geometric codes, wherein the dividing is performed based on the adjusted ensemble.

4. The method according to claim 3 , further comprising:

creating a Latin square of basic random sequences;

dividing a random sequence on m-th row in the Latin square into code-word length n when m-th column in the Euclid geometric codes is divided into code-word length n; and

extracting “1” from the m-th column in the Euclid geometric codes using each random sequence after divided into code-word length n.

5. The method according to claim 3 , further comprising:

creating a Latin square of basic random sequences;

dividing a random sequence on m-th row in the Latin square into code-word length n when m-th row in the Euclid geometric codes is divided into code-word length n; and

extracting “1” from the m-th row in the Euclid geometric codes using each random sequence after divided into code-word length n.

6. The method according to claim 3 , further comprising:

creating a plurality of Latin squares of basic random sequences;

using a Latin square group matrix linked in the column direction;

dividing a random sequence on m-th column in the Latin square group matrix into code-word length n when m-th column in the Euclid geometric codes is divided into code-word length n; and

extracting “1” from the m-th column in the Euclid geometric codes using each random sequence after divided into code-word length n.

7. The method according to claim 3 , further comprising:

creating a plurality of Latin squares of basic random sequences;

using a Latin square group matrix linked in the column direction;

dividing a random sequence on m-th column in the Latin square group matrix into code-word length n when m-th row in the Euclid geometric codes is divided into code-word length n; and

extracting “1” from the m-th row in the Euclid geometric codes using each random sequence after divided into code-word length n.

8. An apparatus for generating check matrixes for Low-Density Parity-Check codes to derive a threshold of Signal to Noise Ratio that provides an error with a value of 0 by analyzing a Sum Product Algorithm for the Low-Density Parity-Check codes, on an assumption that a Log Likelihood Ratio between input/output data at a decoder is approximated in a Gaussian distribution, comprising:

an encoder to

fix a coding rate;

obtain an optimal ensemble, which is an ensemble that minimizes the threshold of Signal to Noise Ratio, of a row and a column weights in a linear programming, wherein the linear programming is employed to search optimal generator functions to maximize a Gaussian noise; and

generate a check matrix for the Low-Density Parity-Check codes in accordance with the ensemble obtained.

9. The apparatus according to claim 8 , wherein the encoder further extracts “b 1 ” at random from each row or each column in Euclid geometric codes based on the ensemble obtained, and

divides each row or each column to generate a check matrix for Irregular Low-Density Parity-Check codes.

10. The apparatus according to claim 9 , wherein the encoder further adjusts a weight distribution in the ensemble obtained such that the total weight number of weight units is equal to an integer, and a sum of the total weight numbers of weight units is equal to the total number of “1”s in Euclid geometric codes, and

divides each row or each column to generate a check matrix for Irregular Low-Density Parity-Check codes based on the adjusted ensemble.

11. The apparatus according to claim 10 , wherein the encoder further creates a Latin square of basic random sequences;

divides a random sequence on m-th row in the Latin square into code-word length n when m-th column in the Euclid geometric codes is divided into code-word length n; and

extracts “1” from the m-th column in the Euclid geometric codes using each random sequence after divided into code-word length n.

12. The apparatus according to claim 10 , wherein the encoder further creates a Latin square of basic random sequences;

divides a random sequence on m-th row in the Latin square into code-word length n when m-th row in the Euclid geometric codes is divided into code-word length n; and

extracts “1” from the m-th row in the Euclid geometric codes using each random sequence after divided into code-word length n.

13. The apparatus according to claim 10 , wherein the encoder further creates a plurality of Latin squares of basic random sequences;

uses a Latin square group matrix linked in the column direction;

divides a random sequence on m-th column in the Latin square group matrix into code-word length n when m-th column in the Euclid geometric codes is divided into code-word length n; and

extracts “1” from the m-th column in the Euclid geometric codes using each random sequence after divided into code-word length n.

14. The apparatus according to claim 10 , wherein the encoder further creates a plurality of Latin squares of basic random sequences;

uses a Latin square group matrix linked in the column direction;

divides a random sequence on m-th column in the Latin square group matrix into code-word length n when m-th row in the Euclid geometric codes is divided into code-word length n; and

extracts “1” from the m-th row in the Euclid geometric codes using each random sequence after divided into code-word length n.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 31, 2003
From: MATSUMOTO, WATARU
To: MITSUBISHI DENKI KABUSHIKI KAISHA
Reel/Frame 015383/0152 →
Priority Claims (1)
JP 2001-397922 · Dec 27, 2001 · national
Continuity (1)
Related Publication 20040186992A1 · Sep 23, 2004