M-ary runlength limited codes for high density optical recording

New optical recording channels have been developed that support unsaturated, M-ary (M/spl ges/3) signaling. In this paper we consider the analysis and design of M-ary runlength limited codes for such channels. These codes are designed using the state splitting algorithm and have improved minimum squared Euclidean distance over an ordinary Adler-Coppersmith-Hassner code. Comparisons are made with Ungerboeck-style amplitude modulation trellis codes with comparable complexity and in some cases the new codes achieve a coding gain of over 2 dB.<
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