Constrained block codes for class-IV PRML channels

We investigate sets of maximal number of fixed-length sequences that can be concatenated without violating certain constraints often required in class-IV PRML channels used in magnetic recording. PRML is a technique that combines partial-response (PR) signaling with maximum-likelihood (ML) sequence estimation in order to combat intersymbol interference and noise, which are common in high density digital magnetic storage channels. The class-IV channel processes independently the even and the odd subsequences of bits with even and odd indices, respectively