A soft decision-directed LMS algorithm for blind equalization

Author

Nowlan, Steven J. ; Hinton, Geoffrey E.

Author_Institution

Comput. Neurosci. Lab., Salk Inst., San Diego, CA, USA

Volume

41

Issue

2

fYear

1993

fDate

2/1/1993 12:00:00 AM

Firstpage

275

Lastpage

279

Abstract

An adaptation algorithm for equalizers operating on very distorted channels is presented. The algorithm is based on the idea of adjusting the equalizer tap gains to maximize the likelihood that the equalizer outputs would be generated by a mixture of two Gaussians with known means. The decision-directed least-mean-square algorithm is shown to be an approximation to maximizing the likelihood that the equalizer outputs come from such an independently and identically distributed source. The algorithm is developed in the context of a binary pulse-amplitude-modulation channel, and simulations demonstrate that the algorithm converges in channels for which the decision-directed LMS algorithms does not converge

Keywords

equalisers; least squares approximations; pulse amplitude modulation; telecommunication channels; PAM channel; binary pulse-amplitude-modulation channel; blind equalization; decision-directed least-mean-square algorithm; soft decision algorithms; very distorted channels; Approximation algorithms; Blind equalizers; Decision feedback equalizers; Delay systems; Digital communication; Gaussian processes; Helium; Least squares approximation; Nonlinear distortion; Transversal filters;

fLanguage

English

Journal_Title

Communications, IEEE Transactions on

Publisher

ieee

ISSN

0090-6778

Type

jour

DOI

10.1109/26.216497

Filename

216497