Improved Trellis-Coding for Partial-Response Channels

New code design methods and Viterbi detector architectures are presented for high-rate trellis-coded partial-response (TCPR) systems. The methods, which extend the matched-spectral-null (MSN) coding technique, use novel code constraints and time-varying detector trellis structures to reduce path memory requirements by as much as a factor of two, relative to previously reported codes, while retaining the other attractive features of MSN codes. The design methods and corresponding time-varying trellis structures are illustrated with several examples. © 1995 IEEE