A fixed-lag particle smoothing algorithm for the blind turbo equalization of time-varying channels

Alberto Gaspar Guimaraes (1) , Boujemaa Ait-El-Fquih (2, 3, 4) , François Desbouvries (5, 2, 3, 4)

1 IME - Instituto Militar de Engenharia=Military Institute of Engineering
2 TSP - CITI - Communications, Images et Traitement de l'Information
3 SAMOVAR - Services répartis, Architectures, MOdélisation, Validation, Administration des Réseaux
4 CNRS - Centre National de la Recherche Scientifique
5 TIPIC-SAMOVAR - Traitement de l'Information Pour Images et Communications

We introduce a novel sequential importance sampling (SIS) algorithm for the blind equalization of doubly selective channels. Our algorithm propagates a Monte Carlo (MC) approximation of the posterior fixed-lag smoothing distribution of the symbols. As we shall see, it is possible to sample particles from the optimal importance distribution and to update the smoothing importance weights accordingly. We next apply the developed method as a SISO (Soft Input Soft Output) equalizer in a turbo receiver framework. The performance evaluation of our algorithm is carried out under different fading scenarios, and the results are compared with a soft iterative channel estimation scheme available in the literature

Mots clés: Blind equalization; Turbo equalization; Sequential importance sampling methods

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

Alberto Gaspar Guimaraes, Boujemaa Ait-El-Fquih, François Desbouvries. A fixed-lag particle smoothing algorithm for the blind turbo equalization of time-varying channels. ICASSP 2008 : IEEE International Conference on Acoustics, Speech and Signal Processing, Mar 2008, Las Vegas, United States. pp.2917 - 2920, ⟨10.1109/ICASSP.2008.4518260⟩. ⟨hal-01378683⟩