Improved Blind Decision Equalizer with self-adapted structure for High Order QAM signals

Christophe Laot (1) , Joël Labat (1)

1 SC - Département Signal et Communications

This paper brings some noticeable improvements to a blind decision feedback equalizer recently introduced and mainly characterized by its self-adapted structure. In its starting-up mode, this equalizer is linear and recursive and controlled by a withening criterion for the recursive part and the Godard criterion for the transversal one. However, in the case of high order QAM signals, the whole performances can be largely improved when the Godard algorithm is gradually replaced by the radius directed algorithm. This novel switching procedure is investigated for a 64-QAM on a typical telephone line and on a severe non minimum phase channel. The results are really convincing since this strategy brings a more accurate equalization, which allows the new equalizer to safely reach its final state of decision feedback equalize (tracking mode). Needless to say that such an improved blind equalizer turns out to be particulary well-suited for applications such as HDTV

Mots clés: Blind Decision Equalizer; QAM signals

Domaines: Traitement du signal et de l'image [eess.SP]

Christophe Laot, Joël Labat. Improved Blind Decision Equalizer with self-adapted structure for High Order QAM signals. Proc. ICT, Jun 1999, Chalkidiki, Grèce. ⟨hal-02149658⟩