Methods and apparatus for decoding LDPC codes
US6633856B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 2001 |
| Grant date | Oct 14, 2003 |
| Priority date | — |
| Expiry date | Mar 5, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M13/6566
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus for decoding codewords using message passing decoding techniques which are particularly well suited for use with low density parity check (LDPC) codes and long codewords are described. The described methods allow decoding graph structures which are largely comprised of multiple identical copies of a much smaller graph. Copies of the smaller graph are subject to a controlled permutation operation to create the larger graph structure. The same controlled permutations are directly implemented to support message passing between the replicated copies of the small graph. Messages corresponding to individual copies of the graph are stored in a memory and accessed in sets, one from each copy of the graph, using a SIMD read or write instruction. The graph permutation operation may be implemented by simply reordering messages, e.g., using a cyclic permutation operation, in each set of messages read out of a message memory so that the messages are passed to processing circuits corresponding to different copies of the small graph.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.