Simple and systematic process for constructing and coding LDPC codes
AssigneeThomson-CSF
InventorPierre André Laurent
Life of this patent
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Abstract
A process for the construction of LDPC codes including N symbols, of which K are free, each code being defined by a check matrix A including M=N−K rows, N columns, and t nonzero symbols in each column. The method includes allocating the same number of nonzero symbols to all the rows of the check matrix A, taking t to be the smallest possible odd number, defining the columns of A such that any two columns of the check matrix A have at most one nonzero value in a common position, and defining the rows of A such that any two rows of the check matrix A have only one nonzero value in a common position.
Claims4
A method for constructing low density parity check (LDPC) codes for protecting binary information trains, each train being composed of N symbols decomposed into N−M useful information symbols Xi and M redundancy information symbols Ym, each code being defined by a check matrix A comprising M<N rows of N columns and t nonzero symbols in each column, comprising:
- allocating a same number of nonzero symbols to each row of the check matrix A;
- setting t equal to an odd number;
- defining the columns of the check matrix A such that any two columns of the check matrix A have a nonzero value in at most one common position;
- and
- defining the rows of the check matrix A such that any two rows of the check matrix A have a nonzero value in only one common position.
Dependencies are inferred from the claim text.