On linear MMSE based turbo-equalization of nonlinear Volterra channels

Bouchra Benammar (1) , Nathalie Thomas (1, 2) , Charly Poulliat (1, 2) , Marie-Laure Boucheret (1, 2) , Mathieu Dervin (3)

1 IRIT-SC - Signal et Communications
2 Toulouse INP - Institut National Polytechnique (Toulouse)
3 THALES [France]

This article deals with Minimum Mean Square Error (MMSE) turbo equalization of nonlinear interference using a volterra series decomposition of the underlying nonlinear channel. Although it has been often argued that linear MMSE based equalization is unsuited for cancelling nonlinear interference, we show that this common belief is not true in a strict sense. By a proper derivation of the linear based MMSE soft equalizer, we are able to show that the underlying structure of the equalizer is equivalent to a Soft Interference Canceller (SIC) treating both the linear and nonlinear interference. Based on these results, approximations are provided for lowering the computational complexity. Links to previously proposed “nonlinear” SIC are emphasized showing that the previously proposed structures are nothing but approximations of a linear MMSE receiver applied to nonlinear ISI channels. Simulations show that significant improvements can be achieved by using the proposed exact and approximate MMSE based turbo-equalizers.

Mots clés: Nonlinear interference; Volterra series; Iterative equalization

Domaines: Synthèse d'image et réalité virtuelle [cs.GR]; Traitement du signal et de l'image [eess.SP]; Traitement des images [eess.IV]; Vision par ordinateur et reconnaissance de formes [cs.CV]; Intelligence artificielle [cs.AI]

Bouchra Benammar, Nathalie Thomas, Charly Poulliat, Marie-Laure Boucheret, Mathieu Dervin. On linear MMSE based turbo-equalization of nonlinear Volterra channels. IEEE International Conference on Acoustics, Speech, and Signal Processing - ICASSP 2013, May 2013, Vancouver, Canada. pp. 4703-4707. ⟨hal-01150348⟩