Optimum decision delay of the finite-length DFE

Gong, Y. and Cowan, C.F.N. (2004) Optimum decision delay of the finite-length DFE. IEEE Signal Processing Letters, 11 (11). pp. 858-861. ISSN 1070-9908 doi: 10.1109/LSP.2004.836943

Abstract/Summary

This work investigates the optimum decision delay and tap-length of the finite-length decision feedback equalizer. First we show that, if the feedback filter (FBF) length Nb is equal to or larger than the channel memory v and the decision delay Δ is smaller than the feedforward filter (FFF) length Nf, then only the first Δ+1 elements of the FFF can be nonzero. Based on this result we prove that the maximum effective FBF length is equal to the channel memory v, and if Nb ≥ v and Nf is long enough, the optimum decision delay that minimizes the MMSE is Nf-1.