Mitsubishi Electric Corporation

Rui Sakai

Hideo Yoshida

Wataru Matsumoto

Yoshikuni Miyata

Takahiko Nakamura

A decoding apparatus includes a row processing unitand a column processing unitfor performing a calculation and an update of probability information with row processing and column processing according to a Min-Sum algorithm on a received signal which is low-density parity-check coded in batches of 1 bit or a predetermined number of bits, a decoded result judgment unitfor determining a decoded result from a hard decision of a posterior value, for performing a parity check on the decoded result, and for judging whether or not the decoded result is correct, and a control unit for controlling iteration of decoding processing by the row processing unitand column processing uniton the basis of the judgment result of the decoded result judgment unit

Decoding apparatus and communications apparatus

When arranging J cyclic permutation matrices I(p) with p rows and q columns (0&#x2266;j&#x2266;J&#x2212;1, 0&#x2266;l&#x2266;L&#x2212;1) in a row direction and also arranging L cyclic permutation matrices I(p) in a column direction so as to generate a regular quasi-cyclic matrix having uniform row and column weights, a quasi-cyclic matrix generating unitconfigures the regular quasi-cyclic matrix by combining cyclic permutation matrices I(p) in each of which matrix elements whose row number is r (0&#x2266;r&#x2266;p&#x2212;1) and whose column number is (r+p) mod p are '1's, and other matrix elements are '0's in such a way that a plurality of cyclic permutation matrices I(p) arranged at, e.g., the 1st row differ from one another.

Check matrix generating device, check matrix generating method, encoder, transmitter, decoder, and receiver

A regular qc matrix is generated in which cyclic permutation matrices with specific regularity are arranged in row and column directions. A mask matrix supporting multiple encoding rates is generated for making the regular qc matrix into irregular. A specific cyclic permutation matrix in the regular qc matrix is converted into a zero-matrix using a mask matrix corresponding to a specific encoding rate to generate an irregular masking qc matrix. An irregular parity check matrix with a LDGM structure is generated, in which the masking qc matrix and a matrix in which the cyclic permutation matrices are arranged in a staircase manner are arranged in a predetermined location.

Inspection matrix generation method, encoding method, communication device, communication system, and encoder

A communication apparatus includes a storage unit, a row processing unit, and a column processing unit. The row processing unit repeatedly performs row processing to calculate a column-processing LLR for each column and each row in a check matrix. The column processing unit calculates a row-processing LLR for each column and each row of the check matrix, and repeatedly performs column processing to store in the storage unit the minimum value k of absolute values of the row-processing LLR. The row processing unit and the column processing unit alternately performs their processing. The row processing unit performs calculation using an approximate minimum value while the column processing unit cyclically updates the minimum k value of each row.

Communication apparatus and decoding method

An error correction coding apparatus is disposed to generate a low-density parity-check codefrom an input information sequenceby using a low-density parity-check matrix which satisfies a predetermined weight distribution, and includes a low-density parity-check matrix output meansfor forming the above-mentioned low-density parity-check matrix by continuously arranging a number of rows in each of which the same number of cyclic-permutation matrices as the row weight are arranged, the number of rows satisfying the above-mentioned predetermined weight distribution, and then gradually increasing or decreasing the row weight, and for outputting the above-mentioned low-density parity-check matrix.

Error correction coding apparatus

A regular quasi-cyclic matrix is prepared, a conditional expression for assuring a predetermined minimum loop in a parity check matrix is derived, and a mask matrix for converting a specific cyclic permutation matrix into a zero-matrix based on the conditional expression and a predetermined weight distribution is generated. The specific cyclic permutation matrix is converted into the zero-matrix to generate an irregular masking quasi-cyclic matrix. An irregular parity check matrix in which the masking quasi-cyclic matrix and a matrix in which the cyclic permutation matrices are arranged in a staircase manner are arranged in a predetermined location.

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Tokyo, Japan

Rui Sakai