Method and decoding apparatus using linear code with parity check matrices composed from circulants
AssigneeSeagate Technology LLC
InventorsAlexander Vasilievich Kuznetsov, Bane Vasic, Erozan Mehmet Kurtas
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Abstract
The present invention provides a novel method and apparatus for decoding digital information transmitted through the communication channel or recorded on a recording medium. The method and apparatus are preferably applied in the systems where data is encoded using regular LDPC codes with parity check matrices composed from circulants (a matrix is called a circulant if all its column or row are cyclic shifts each other).
Claims20
A communication system for decoding data which is encoded with a linear low density parity check code having a parity check matrix H constructed from circulants, the communication system comprising:
- a channel detector which provides as an output log-likelihood ratios, each log-likelihood ratio being indicative of a probability that a transmitted bit u of a code word is equal to 1;
- a low density parity check code decoder coupled to the channel detector and receiving the log-likelihood ratios λ as an input, the decoder configured to convert the log-likelihood ratios into real numbers Λ, to generate corrections μ to the log-likelihood ratios λ, and to generate corrected log-likelihood ratios λ′ as a function of the log-likelihood ratios λ and the corrections μ, the decoder providing as an output a binary signal.
A method of decoding data which is encoded with a linear low density parity check code having a parity check matrix H constructed from circulants, the method comprising:
- generating log-likelihood ratios with a channel detector, each log-likelihood ratio being indicative of a probability that a transmitted bit u of a code word is equal to 1;
- converting the log-likelihood ratios λ into real numbers using a low density parity check code decoder;
- generating, using the low density parity check code decoder, corrections μ to the log-likelihood ratios λ;
- generating, using the low density parity check code decoder, corrected log-likelihood ratios λ′ as a function of the log-likelihood ratios λ and the corrections μ;
- and
- providing a binary signal as an output of the low density parity check code decoder.
A communication system for decoding data which is encoded with a linear low density parity check code having a parity check matrix H constructed from circulants, the communication system comprising:
- a channel detector which provides as an output log-likelihood ratios, each log-likelihood ratio being indicative of a probability that a transmitted bit u of a code word is equal to 1;
- and
- decoding means for receiving the log-likelihood ratios λ as an input and for providing as an output a binary signal.
Dependencies are inferred from the claim text.