Apparatus and method for layered decoding in a communication system using low-density parity-check codes
A channel decoding apparatus and method in a communication system using Low-Density Parity-Check (LDPC) codes are provided in which an encoded signal is received from a transmitter and decoded using a parity-check matrix. At least one of input orders and output orders of the parity-check matrix are determined so that same values are not overlapped in a column direction between the at least one of the input orders and the output orders.
1. A channel decoding method comprising the steps of:
extracting a parity-check matrix;
grouping rows of the parity-check matrix into one or more groups;
grouping rows of each group into one or more sub-groups, if the each group has two or more non-zero elements in a column direction; and
determining input and/or output orders for each row of the one or more sub-groups,
wherein each row of the one or more sub-groups is processed in parallel.
2. The channel decoding method of claim 1 , wherein grouping rows comprises:
grouping rows of the parity-check matrix to avoid overlapping input and/or output values in the column direction between rows of each group.
3. The channel decoding method of claim 1 , wherein determining comprises:
determining at least one of the input orders and the output orders of the grouped rows to avoid overlapping input and/or output values in the column direction between layers of each group.
4. The channel decoding method of claim 1 , wherein, when a Quasi-Cyclic Low-Density Parity-Check (QC-LDDC) code is layer-decoded, input and/or output values are not overlapped in the column direction between adjacent layers in the parity check matrix, wherein the QC-LDPC has one block being a sum of two or more permutation matrices.
5. A channel decoding apparatus comprising:
an extractor for extracting a parity-check matrix; and
a controller for grouping rows of the parity-check matrix into one or more groups, grouping rows of each group into one or more sub-groups, if the each group has two or more non-zero elements in a column direction, and determining input and/or output orders for each row of the one or more sub-groups,
wherein each row of the one or more sub-groups is processed in parallel.
6. The channel decoding apparatus of claim 5 , wherein the controller groups the rows of the parity-check matrix so that input and/or output values are not overlapped in the column direction between rows of each group.
7. The channel decoding apparatus of claim 5 , wherein at least one of the input orders and the output orders of the grouped rows are determined so that input and/or output values are not overlapped in the column direction between layers of each group.
8. The channel decoding apparatus of claim 5 , wherein when a Quasi-Cyclic Low-Density Parity-Check (QC-LDPC) code is layered-decoded, input and/or output values are not overlapped in the column direction between adjacent layers in the parity check matrix, wherein the QC-LDPC has one block being a sum of two or more permutation matrices.