On initialization strategies for blind adaptive DFEs

We consider a generic blind adaptive DFE initialization strategy which begins with blind adaptation of a linear structure minimizing MSE followed by a switch to decision-direction under the nonlinear DFE structure. We show that this very natural scheme is not always successful in reaching the switching threshold, particularly for high order constallations, and for designs using short length filters. Furthermore, we review two previously proposed DFE initialization procedures that are based on a similar philosophy, and show that they share the advantages and shortcomings of this strategy