The synthesis of a new DC-free code with asymmetrical runlength constraints developed with the ACH-algorithm

We present a new dc-free code suitable for use on binary asymmetrical channels. Write-once recording of optical discs is an example of a channel requiring asymmetrical runlength constraints. The new code was developed with the well-known Adler-Coppersmith-Hassner Algorithm. The detailed synthesis of the new code is presented, together with its error behaviour and power spectral density. We have previously found that dc-constrained codes which do not have finite memory are very difficult to develop with the ACH-algorithm.