A blind adaptation algorithm for decision feedback equalizers with fractionally-spaced feedforward filters

R. Zukunft1, S. Haar2, T. Magesacher2
1Inst. for Integrated Circuits - BRIDGELAB, Munich Univ. of Technol., Germany
2Institute for Integrated Circuits, Munich University of Technology, Munich, Germany

Tóm tắt

This paper introduces a blind adaptation algorithm for decision feedback equalizers (DFE) which employ an oversampled feedforward filter. The coefficient set of the feedback filter is obtained from a pure recursive filter which is designed to whiten the oversampled input signal in the sense that it minimizes correlations between the original signal and versions of it which are shifted by multiples of the symbol duration. This recursive filter is adapted by the introduced multichannel extension of the hyperstable adaptive filter algorithm (HARF). The forward equalizer is adapted by the standard constant modulus algorithm (CMA). Simulation results show that the introduced technique is able to equalize a class of channels for which the standard CMA algorithm fails to converge and that it also works well in a digital subscriber line (DSL) environment.

Từ khóa

#Decision feedback equalizers #Nonlinear filters #DSL #IIR filters #Blind equalizers #Convergence #Adaptive filters #Feedback circuits #Signal design #Data communication

Tài liệu tham khảo

10.1109/26.469441 lee, 1994, Digital Commu-nication macchi, 1995, Adaptive Processing: The LMS approach with applications in transmission! 10.1109/26.911453 10.1109/TCOM.1980.1094608 10.1109/26.701319 10.1109/WCNC.1999.796762 lelslanc, 2001, Blind adapted, prewhitened constant modulus algorithm, Proc IEEE Int Con! Commun 10.1109/SPAWC.1999.783063 regalia, 2001, On the convergent points of blind adaptive IIR equalizers, Proc IEEElEURASIP Workshop on Nonlinear Sig and Image Proc 10.1109/5.720245 10.1109/18.391242 10.1109/PROC.1985.13298