Performance evaluation of the MMSE delayed decision feedback sequence detector

In signal equalization, a technique that allows reduction of the number of states of the Viterbi detector is the Delayed Decision Feedback Sequence Detector (DDFSD). In order to achieve good performance, it is crucial to operate an appropriate prefiltering of the received sequence before the DDFSD. This paper is devoted to performance evaluation of the DDFSD when the prefilter of a minimum mean square error decision feedback equalizer is adopted. The union upper bound is used to evaluate the probability of first-event error, and truncation of the sum to the error sequences that dominate the performance is discussed.