Design of adaptive equalizer for digital subscriber loop using 2B1Q code

Author

Wei, Che-Ho ; Hsiung, Frank ; Koong, Sheng-Yaw

Author_Institution

Inst. of Electron., Nat. Chiao Tung Univ., Hsin Chu, Taiwan

fYear

1990

fDate

24-27 Sep 1990

Firstpage

672

Abstract

An adaptive equalizer structure for a digital subscriber loop using 2B1Q code is presented to combat intersymbol interference (ISI). A shaping filter is introduced to eliminate the precursor ISI. The design of this adaptive equalizer is based on a decision feedback equalizer (DFE) structure without feedforward section employing a clipped least-mean-square algorithm for estimating the postcursor of the channel´s impulse response. A new variable stepsize method and a shape-oriented adjustment method are used to improve the convergence speed of the adaptive equalizer. Software simulation demonstrates the feasibility of the algorithm and structure. A hardware circuit is implemented using a logic cell array for real-time testing

Keywords

equalisers; interference suppression; intersymbol interference; subscriber loops; 2B1Q code; DFE; ISI; LMS algorithm; adaptive equalizer; clipped least-mean-square algorithm; convergence speed; decision feedback equalizer; digital subscriber loop; intersymbol interference; logic cell array; real-time testing; shape-oriented adjustment method; shaping filter; variable stepsize method; Adaptive equalizers; Algorithm design and analysis; Circuit testing; Convergence; DSL; Decision feedback equalizers; Filters; Intersymbol interference; Logic arrays; Logic testing;

fLanguage

English

Publisher

ieee

Conference_Titel

Computer and Communication Systems, 1990. IEEE TENCON'90., 1990 IEEE Region 10 Conference on

Print_ISBN

0-87942-556-3

Type

conf

DOI

10.1109/TENCON.1990.152695

Filename

152695