Design of hyper states for reduced-state sequence estimation

A new method for the design of hyper states for reduced-state sequence estimation of trellis coded signals is proposed. Examples are given for trellis coded modulation (TCM) over channels with intersymbol interference (ISI). The complexity of the super trellis resulting from the combination of the TCM and ISI trellises is reduced by an algorithm that applies set partitioning principles to the set of super states. The method often allows one to achieve asymptotic optimality at a low level of complexity. Simulations and comparisons with other methods show the superior performance of the proposed class of reduced-state sequence estimators (RSSE)