A NEW APPROACH TO SEQUENTIAL DETECTION

The known suboptimal sequential detection methods need a minimum-phase signal as input for achieving good performance. As a consequence the received signal must be first transformed to minimum-phase by an adapt ive prefilter if simplified detection methods are applied. This rounda bout way is avoided in a novel algorithm for sequential detection, whe re the metric calculation itself is fitted to the special situation of the compare-and-select procedure. The detection method uses two diffe rent metrics, one for comparing paths, which have merged in a common t rellis-state, the other for comparing paths which have just emerged fr om a common state. In this way the usual adaptive prefilter can be sav ed, because the proposed detector does not require a minimum-phase sig nal at its input. Simulation results show excellent management of dist orted and noisy signals.