Posts filed under ‘Coding and Information Theory’
I’ve released a new version of my software for Low Density Parity Check (LDPC) codes. These error-correcting codes were invented by Robert Gallager in the early 1960′s, and re-invented and shown to have very good performance by David MacKay and myself in the mid-1990′s. The decoding algorithm for LDPC codes is related to that used for Turbo codes, and to probabilistic inference methods used in other fields. Variations on LDPC and Turbo codes are currently the best practical codes known, in terms of their ability to transmit data at rates approaching channel capacity with very low error probability.
This new version has only a few bug fixes and minor enhancements. The big change is that I’ve put up the source code as a Github repository, that uses the git source code control system. This should make it easier for other people to create their own extensions of the software. The software is available here, and the Github repository is here.
For me, this is also an exercise in learning about git and Github. From my initial experience, git does seem better than the source code control systems I’ve used previously (which are Subversion, CVS, and the “modify” utility of the Kronos operating system for the CDC 6000 series of computers). The help pages are a bit cryptic in places, though, at least for the novice user…