Systematic Modification of Parity-Check Matrices for Efficient Encoding of LDPC Codes

An algorithm for efficient encoding of LDPC codes is presented that does not impose any restrictions on the construction of the parity-check matrices. The algorithm modifies the parity check matrix, without changing the subspace spanned by its rows, by removing linear dependent rows and adding a small number of new rows such that the graph-based message-passing encoder will not get stuck in a stopping set. The added rows are designed by a new algorithm which is based on the notion of the "key set". The encoder exploits the sparseness of the paritycheck matrix, and the encoding complexity grows almost linear with the blocksize, because the number of added rows, which may not be sparse, is relatively small.

• Type: Conference
• Year: 2007
• Where: ICC
• Authors: Mohamed Shaqfeh, Norbert Görtz
• Keywords: Added Rows, Communications, Graph-based Message-passing Encoder, ICC 2007, Linear Dependent Rows