Optimizing Sparse Graph Codes over GF(q)

David J C MacKay

This note explains the method used by Davey and MacKay to set the non-zero entries in low-density parity-check codes over GF(q), and gives explicit prescriptions.

The software used for exhaustive search is available from here (hzFFTe.p).

Matthew Davey's software which makes random assignments and ranks them is available from here (hzFFTe.p).

The tar file containing the program outputs is here (hz.tar).

This work was supported by a faculty partnership award from IBM Zurich Research labs.

postscript (Cambridge UK).

postscript (Canada mirror).

pdf (Cambridge UK).

pdf (Canada mirror).

All postscript files are compressed with gzip - see this page for advice about gzip, if needed.


related publications.
David MacKay's: home page, publications. bibtex file.
Canadian mirrors: home page, publications. bibtex file.