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http://dx.doi.org/10.7840/kics.2015.40.3.419

A New Decision-Directed Equalization with Improved Blind Convergence Properties by Error Scaling  

Oh, Kil Nam (Dept. of Optical Commun. Eng., Gwangju Univ.)
Publication Information
The Journal of Korean Institute of Communications and Information Sciences / v.40, no.3, 2015 , pp. 419-424 More about this Journal
Abstract
The Decision-directed (DD) algorithm is known to be not effective to initialize a blind equalizer in the channel conditions when the eye diagram of received signals is completely closed because it can not open the eye diagram enough. In this paper, we propose a new error to replace the error of the conventional DD algorithm. The new DD error is the conventional DD error scaled by the modulus of symbol decision, new DD algorithm using this error is effective to open the closed eye diagram in early stage of equalization unlike the conventional DD. The new DD algorithm appling the new error is showed excellent convergence characteristics as compared to the CMA widely used in blind initialization, particularly, is useful for equalization of signals having multimodulus. The performance of the new DD algorithm is verified through the simulation for the higher-order QAM signals.
Keywords
Error scaling; Decision-directed; Blind convergence; Higher-order QAM; Multilevel modulus;
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