Decoding low density parity check codes
US7000167B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 8, 2002 |
| Grant date | Feb 14, 2006 |
| Priority date | — |
| Expiry date | Jul 23, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M13/1515
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method for decoding Low Density Parity Check (LDPC) codes comprises executing a sum product algorithm to recover a set of information bits from an LDPC code represented as a bipartite graph of symbol nodes and check nodes, the sum product algorithm being responsive to input log likelihood ratios associated with the symbol nodes. The check nodes are updated by generating a set of forward difference metrics and a set of backward difference metrics in dependence on the ratios of logarithmic probabilities each associated with a corresponding symbol node of the LDPC code, updating each metric in the set of forward difference metrics in dependence on the absolute value of the log likelihood ratio associated with the symbol node and the absolute value of the previous metric in the set, updating each metric in the set of backward difference metrics in dependence on the absolute value of the log likelihood ratio associated with the symbol node and the absolute value of the previous metric in the set, and generating log likelihood ratios to be propagated back to each symbol node in dependence on the updated sets of forward and backward difference metrics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.