Reduced-complexity sequence estimation using state partitioning

A reduced-state sequence estimator (RSSE) for linear dispersive channels is described. The technique is based on partitioning the set of all channel states in a way that defines a trellis with fewer states. The new technique generalizes trellises that were previously obtained by Duel-Hallen and Heegard (1989) and Eyouboglu and Qureshi (1988). While the approach followed by Duel-Hallen results in powers of two-state trellises, the new technique generates trellises with an arbitrary number of states. Using the state partitioning approach one could also generalize the trellises obtained by Eyouboglu. Therefore, the approach described in this paper provides a better performance/complexity tradeoff.