Improved distance M-ary (d,k) codes for high density recording

We consider the problem of coding for a high density recording channel. New recording media have been developed that support unsaturated, M-ary (M/spl ges/3) signaling. This paper is concerned with the analysis and design of M-ary runlength limited (RLL) codes for multi-amplitude, linear recording AWGN channels. The codes achieve the largest known coding density and have improved minimum distance over an ordinary Adler-Coppersmith-Hassner code designed via the state splitting algorithm. Comparisons are made with Ungerboeck-style trellis codes with comparable complexity.<
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