MMSE-based iterative equalization with soft feedback for QAM transmission over sparse channels

Author

Rossler, J.F. ; Gerstacker, Wolfgang H. ; Huber, Johannes B.

Author_Institution

Erlangen-Nurnberg Univ., Erlangen, Germany

Volume

1

fYear

2003

fDate

23 Feb.-1 March 2003

Firstpage

566

Abstract

An equalization algorithm, based on soft-decision feedback and designed for transmission with square QAM constellations, is introduced. The algorithm employs a minimum mean-squared error (MMSE) filter in each iteration in order to refine the data estimates. The rule for generating soft decisions is adapted continuously to the current state of the algorithm. It is shown that the algorithm is especially well suited for transmission over certain sparse frequency-selective fading channels where optimum schemes are far too complex. A minimum mean-squared error decision-feedback equalizer (MMSE-DFE) is clearly outperformed for this application.

Keywords

decision feedback equalisers; fading channels; filtering theory; iterative methods; least mean squares methods; parameter estimation; quadrature amplitude modulation; MMSE filter; data estimates; decision-feedback equalizer; equalization algorithm; frequency-selective channels; frequency-selective fading channels; iterative equalization; minimum mean-squared error filter; soft-decision feedback; sparse channels; square QAM constellations; Algorithm design and analysis; Decision feedback equalizers; Delay estimation; Filtering; Filters; Intersymbol interference; Iterative algorithms; Iterative decoding; Maximum likelihood estimation; Quadrature amplitude modulation;

fLanguage

English

Publisher

ieee

Conference_Titel

Telecommunications, 2003. ICT 2003. 10th International Conference on

Print_ISBN

0-7803-7661-7

Type

conf

DOI

10.1109/ICTEL.2003.1191472

Filename

1191472