1. Field of the Invention
The present invention relates to signal processing, and, in particular, to error-correction encoding and decoding techniques such as low-density parity-check (LDPC) encoding and decoding.
2. Description of the Related Art
Low-density parity-check (LDPC) encoding is an error-correction encoding scheme that has attracted significant interest in recent years due in part to its ability to operate near the Shannon limit and its relatively low implementation complexity. LDPC codes are characterized by parity-check matrices, wherein, in each parity-check matrix, the number of elements in the matrix that have a value of one is relatively small in comparison to the number of elements that have a value of zero. Over the last few years, various methods of performing LDPC encoding have been developed. For example, according to one relatively straightforward method, LDPC encoding may be performed by multiplying a generator matrix, derived from the parity-check matrix, by user data to generate LDPC codewords. A discussion of this and other LDPC encoding methods may be found in Richardson, “Efficient Encoding of Low-Density Parity-Check Codes, IEEE Transactions on Information Theory, Vol. 47, No. 2, pgs. 638-656, February 2001, and Thong, “Block LDPC: A Practical LDPC Coding System Design Approach,” IEEE Transactions on Circuits and Systems: Regular Papers, Vol. 52, No. 4, pgs. 766-775, April 2005, the teachings all of which are incorporated herein by reference in their entirety.