Codes preventing Quasi-catastrophic error propagation in partial-response systems

The problem of preventing quasi-catastrophic error propagation in maximum-likelihood and reduced-state sequence detection for multilevel partial-response channels with transfer functions (1 - Dp) and (1 + Dp) is studied. Channel input sequences that limit the length of minimum-distance error events to L symbols are exhaustively characterized by finite-state transition diagrams. An efficient procedure for computing the capacity associated with these transition diagrams is given, ('odes preventing quasi-catastrophic error propagation that can be realized by finite-state encoders and block decoders are constructed.